> For the complete documentation index, see [llms.txt](https://help.sipgate.de/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.sipgate.de/cloud-telefonanlage/en/using-sipgate/fax/faxdrucker-windows-fehler-und-loesungen.md).
# Fax printer Windows: errors and solutions
#### Frequently Asked Questions
How can I improve the quality?
The source document should be black and white and without grayscale.
Can the fax printer be found in the Windows Store?
No, it is not planned for now.
Can the fax printer be installed on a Surface with an ARM CPU?
No, the fax printer only works with x86/x64 Intel/AMD CPUs
Is the upload of the temporary fax PDF encrypted?
From the fax printer to the web server, the data is transmitted encrypted via SSL port 443 using TLS 1.2.
Why can't I see any contacts?
**Cause 1:** there are only phone contacts\
**Solution 1:**\
\- Import contacts via Google/CSV, make sure that phone/fax was imported\
\- Close the fax printer if it is open and restart via Print; fax contacts should now be loaded\
**Cause 2:** there are more than 1000 contacts\
**Solution 2:** if possible, use fewer than 1000 contacts; otherwise always enter the fax number, as search only works for up to 1000 contacts
How can I send faxes faster?
Use this short introduction to be able to send faxes quickly:
* Send fax, wait until status "Document successfully transmitted"
* Close fax printer "click X in the top right"
* Document ➔ Print ➔ sipgate fax printer send new fax
* Check fax status in the sipgate account ➔ event list; from "Document successfully transmitted" the PDF is on the sipgate server, which then sends the fax. You only need to wait in the fax printer if you want to see the transmission status until the end.
#### Possible error codes
Below you will find a short explanation of certain error codes
F400 "Transmission failed, please try again later (F400)
**Log:** "failed to send fax: An error occured while sending the request" when the API is blocked in the fax printer after successful login\
**Cause:** Software firewall blocks requests from the fax printer to our API [https://api.sipgate.com](https://api.sipgate.com/) 217.10.72.56 and [https://login.sipgate.com](https://login.sipgate.com/) **or** Internet in general\
**Solution:** allow the fax printer to access the network/Internet in the software/router firewall\
**Approach**: C://Users/"Name"/AppData/Local/sipgateFaxdrucker/Logs check whether there is an error message with date and time matching the fax transmission\
**Cause:** sipgate has an outage, API does not respond\
**Solution:** Status page: check and wait
Login works, fax line loaded, error when sending (F400)
**Log:** "Error: 0 : Failed! Response code was: GatewayTimeout" and "Warning: 400 : Sending failed: Api returned no sessionId"\
**Cause:** api.sipgate.com cannot be reached\
**Solution:** Check in the firewall rules whether api.sipgate.com / 217.10.72.56 is being temporarily blocked
Make sure that you have an Internet connection.
\*\*Cause:\*\* there is no Internet connection when sending a fax\
**Solution:** Check and repair the Internet connection, then repeat fax sending
F500: The transmission of the fax to our systems failed for an unknown reason.
Please contact customer support, ideally with a description of how to reproduce the behavior.
F413: The transmission of the fax failed because the file is larger than 9 MB.
The transmission of the fax to our systems failed because the file is larger than 9 MB.
F415: The transmission of the fax failed because the file is invalid.
The transmission of the fax to our systems failed because the file is invalid. Try a different file type.
#### Possible errors and solutions
Error message: The application requires .Net Framework 4.6.1 (4.3.2.0)
**Cause**: You are using Windows 7 Service Pack 1 without .Net Framework 4.6.1\
**Solution**: download and install .Net Framework 4.6.1 for Windows 7 from Microsoft [Link](https://www.microsoft.com/de-de/download/details.aspx?id=49982)\
**Note**: fax printer 4.2+ cannot be used on Windows 7
Error message: The application requires .Net Framework 4.6.2 (4.3.3.0)
**Cause**: Win 7/8 is missing .Net Framework 4.6.2, which is required by the fax printer\
**Solution**: [.Net Framework 4.6.2](https://support.microsoft.com/de-de/topic/das-net-framework-4-6-2-offlineinstallationsprogramm-f%C3%BCr-windows-9dce3874-a9e5-9b11-289d-5594824aafe0) install it; fax printer installation should now work
Error message: FaxUI — Object reference not set to an instance of an object
**Cause**: sipgate Fax Printer 3.24 is installed and can no longer be used\
**Solution**: uninstall sipgate Fax Printer 3.24, install new fax printer See [Windows Apps](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/Faxdrucker3.24Deinstallation.png)
Error: fax printer is missing from the list of printers after installation
**Cause 1**: Task Manager ➔ Services ➔ Spooler "Print Queue" ➔ Stopped\
**Solution 1**: Task Manager ➔ Services ➔ Spooler "Print Queue" ➔ right-click "Start"\
**Cause 2:** Anti-virus software has blocked a registry entry\
**Solution 2:** Uninstall the fax printer, reinstall it, disable the anti-virus software\
**Note 2:** "repair" did not help
Error message: "error":"unknown_error"
**Cause standard browser:** Browser cache knows the login token, does not refresh the token (Opera)\
**Solution standard browser:** Clear browser cache, fax printer login now works\
**Workaround**: Windows ➔ Default apps ➔ Browser: set a different browser, log in to the fax printer ➔ change the default browser back again\
\- Logout/login now also works with the previous default browser
Error message: "Authentication not possible." / Login failed!
**Log analysis:** C://Users/"Name"/AppData/Local/sipgate Faxdrucker/Logs\
\- sipgate Faxdrucker Critical: 0 : Could not perform code exchange: The remote server returned an error: (407) Proxy authentication required.\
\- sipgate Faxdrucker Critical: 0 : Could not perform code exchange: in Sipgate Faxdrucker.Authentication\
**Cause**: in the firewall, api.sipgate.com / login.sipgate.com is allowed, but sipgate.com is blocked\
**Solution**: allow api.sipgate.com / login.sipgate.com / sipgate.com port 443 (TLS 1.2) in the firewall
Error message: Login failed! / Error during login
**Log analysis:** C://Users/"Name"/AppData/Local/sipgateFaxdrucker/Logs\
\- sipgateFaxdrucker Critical: 0 : Error Authenticating: access\_denied\
**Cause**: after logging in with email/password, a prompt appears; here "[Cancel](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/ZugriffFaxErlauben.png)" was clicked\
**Solution**: log in with email/password and the fax printer [Allow access](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/ZugriffFaxErlauben.png)
Error: clicking "log in in browser" + "No Internet"
**FireFox**: "Page not found"\
**Opera**: "No Internet"\
**Chrome**: "The website cannot be reached"\
**Cause:** no Internet / network cable not connected etc.\
**Solution:** Connect Internet / network cable
Error: clicking "log in in browser" + "No connection/failed"
**Firefox:** FireFox cannot establish a connection to the server at 127.0.0.1:51007.\
**FireFox + sipgate cookie**: Object reference not set to an instance of an object. [Image](https://sipgate.zendesk.com/knowledge/articles/211585785/de?brand_id=559261\&return_to=%2Fhc%2Fde%2Farticles%2F211585785)\
**FireFox without sipgate cookie**: Error: connection failed\
**Chrome**: Your Internet connection is blocked\
**Edge Chromium:** Your Internet access is being blocked\
**Opera**: Object reference not set to an instance of an object. [Image](https://sipgate.zendesk.com/knowledge/articles/211585785/de?brand_id=559261\&return_to=%2Fhc%2Fde%2Farticles%2F211585785)\
**Opera**: The website cannot be reached 127.0.0.1 refused the connection [Image](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/OperaFirewallBlock02.png)\
**Cause**: in the software firewall, access from the fax printer to the Internet is blocked [Kaspersky](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/KasperskyZugriffBlockiert.png)\
**Solution**: allow Internet access in the software firewall
Error: clicking "log in in browser" does not open the browser
C://Users/"Name"/AppData/Local/sipgateFaxdrucker/Logs\
[System.Net](http://system.net/).Sockets.SocketException: Access to a socket was denied because of the socket's access permissions 217.10.72.54:443\
**Cause 1**: Windows ➔ Outbound rules ➔ sipgate Fax Printer rule blocking IP 217.10.72.54\
**Solution 1**: Windows ➔ Outbound rules ➔ delete sipgate Fax Printer rule or allow access\
**Log analysis:**\
sipgateFaxdrucker Warning: 0 : Did not fetch balance due to missing access rights: Balance endpoint returned 403: Forbidden for this user\
**Cause 2**: unclear\
**Solution 2**: send logs to sipgate support with the fax printer login email that is affected.
Error: login data is not saved permanently
**Cause:** Software X prevents system changes or software Y deletes config.dat\
**Problem:** Login data is deleted C://Users/"Name"/AppData/Local/sipgateFaxdrucker/config.dat\
**Example: DeepFreeze** was activated before fax printer login data was entered; after restarting the PC, the fax printer login data is deleted from C://Users/"Name"/AppData/Local/sipgateFaxdrucker/config.at\
**Solution DeepFreeze:** Disable DeepFreeze via administrator, log in to the fax printer, set the DeepFreeze system point and activate DeepFreeze; data should now be stored permanently\
**Example: McAfee Anti-Virus:** Scan drive C:// and check whether McAfee deleted the config.dat\
**Solution McAfee Anti-Virus:** Restore config.dat and mark it as trusted
Error: Windows print job reports "Error printing" — print job deletes itself
"Document.pdf" could not be printed by the printer.\
**Cause**: fax printer is uninstalled; there is only a renamed fax printer entry left\
**Solution**: Windows ➔ Printers ➔ delete renamed printer entry "Remove device"\
\- install fax printer, optionally change the name sipgate fax printer back
Error: print job ends up in print queue / fax printer does not open (user)
**Analysis 1: Windows 10/11 + user**: fax printer starts as [process](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/ProzessFaxdrucker.png) but not as user\
**Solution 1 Windows 10/11 user**: install fax printer 4.3.3.0\
**Workaround 1 Windows 10/11 + user**:\
\- cancel print job if present\
Start C:/Programme/sipgateFaxdrucker/sipgateFaxdrucker.exe, log in to sipgate, fax printer should now be logged in\
\- fax printer **close**, here it is not possible to enter a fax number\
// starting once is necessary to obtain "user rights"\
\- Document ➔ Print ➔ Fax printer ➔ fax printer now opens, enter fax number\
\- restart sipgateFaxdrucker.exe manually when the user is logged off or the PC is restarted\
**Analysis 2:** %LocalAppData%\sipgateFaxdrucker\Logs\
Log error: sipgateFaxdrucker Critical: 0 : error loading credentials: The array must not be NULL\
**Problem 2: login data cannot be found/read:**\
C:\Users\Name\AppData\Local\sipgateFaxdrucker\config.dat\
**Cause 2:** unclear, possibly anti-virus software that deletes config.dat / moves it to quarantine\
**Solution 2:** unclear, check antivirus / firewall
Error: print job ends up in print queue / fax printer does not open (Win Server)
**Cause Windows 2016/2019 Server + WinPC user:**\
Redmon (Redirect Port Monitor) starts faxprinter.exe as user "SYSTEM" instead of local user, so you cannot see the fax printer GUI/dialog because there are not enough rights\
**Solution Windows 2016/2019 Server + Windows user:** Install fax printer 4.3.3.0\
**Workaround Windows 2016/2019 Server:**\
(contact a server admin or IT service provider for implementation)\
\- delete all sipgate fax printer registry entries if the fax printer is already installed\
\- create a local admin\
\- perform fax printer installation with the "local admin"\
\- log in as domain admin and set all rights under **Security** to domain users and SYSTEM\
\- local admin can now be deleted / or you may want to delete it for security reasons\
\- fax printer starts; the first start takes 1-2 minutes, afterwards it starts faster
Error: fax line is empty + no contacts found + "Send fax" is gray
**Error: clicking "fax line" /** [**get groupfaxlines An error occured while sending the request. get groupfaxlines**](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/ErrorOccuredWhileSendingRequest.png)\
**Cause 0**: software/hardware firewall blocks requests to api.sipgate.com\
**Solution 0**: allow software/hardware firewall access to api.sipgate.com\
**Example**.: Fritz Box ➔ Internet ➔ Filter ➔ Lists ➔ Blocked websites [edit ➔](http://192.168.178.1/#/) api.sipgate.com\
**Example**.: Kaspersky ➔ Settings ➔ Protection ➔ Firewall ➔ Packet rules ➔ custom rule blocking api.sipgate.com / 217.10.72.56\
**Example**.: C:\Windows\System32\drivers\etc\hosts entry 127.0.0.1 api.sipgate.com\
\&#xNAN;**"Send fax" button is still gray / cannot be clicked**\
**Cause 1:** not enough credit\
**Solution 1:** top up credit\
**Cause 2:** invalid fax number entered\
**Solution 2:** Check whether the fax number was entered correctly / no special characters\
The following prefixes cannot be used: 0137, 0138, 01212, 01807, 0185, 0181, 0188, 0900 and 118xx\
**Cause 3:** no fax line selected / the user may not have fax service\
\- sipgate free has no WebFax ➔ the S/M/L plan must be used\
**Solution 3:** Select fax line, possibly switch to an S/M/L plan\
**Cause 4:** unclear\
**Approach 4:** Check C://Users/"Name"/AppData/Local/sipgateFaxdrucker/Logs / send to support\
**Solution 4:** unclear
Error: Your credit is insufficient. (at least 1.79 ct)
**Cause**: you should not have 0€ credit or negative credit in the sipgate account\
**Note**: despite free minutes in the trial period, you have 0€ credit\
**Solution**: none; the fax printer can only be used with credit after the trial period\
**Different**: use WebFax; the WebFax in the customer area can use free minutes and credit
Error: fax printer login menu does not open after about 1 min "printed file is too large"
**Description**: fax printer is listed among printers; when printing document->fax printer, the login menu does not open, after 1 min an error message appears: file too large\
**Cause**: file is larger than 9 MB\
**Solution**: reduce file size
Error: black and white document is sent as a black background + red text
**Cause:** the fax printer is stored as a color printer, which is implemented incorrectly in at least Adobe\
**Solution: fax printer** install 4.3.3.0 / distributed via auto update\
**Windows 10 ➔** Settings ➔ Printers & scanners ➔ sipgate fax printer ➔ Manage ➔ Printing preferences ➔ Paper/Quality: Save black and white printer\
**Windows 11 ➔** Settings ➔ Bluetooth & devices ➔ Printers & scanners ➔ sipgate fax printer ➔ Printer preferences ➔ Paper/Quality ➔ Black and white\
**Cause Adobe Acrobat Reader:** Print ➔ fax printer: "Save color/toner" enabled [Image\_01](https://github.com/sipgate/helpcenter-gitbook/tree/main/cloud-telefonanlage/.gitbook/assets/AdobeReaderFarbe.png)\
**Solution Adobe Acrobat Reader:** Print ➔ fax printer ➔ "in grayscale (black and white)
Error: "ghostscript errorSystem.Runtime.InteropServices.ExternalExeption (0xFFFFFF9C): Ghostscript conversion error in SipgateFaxdrucker.GhostScript.GhostScript64.CallApi(String[] args) in \GhostScript64.cs:line 32"
**Problem:** the Ghostscript in the fax printer cannot convert the document to PDF\
**Cause:** Adobe PDF with form field such as signature\
**Solution:** Take a screenshot and send it as a fax via Print
You can find a local log here: C://Users/"Name"/AppData/Local/sipgateFaxdrucker/Logs\
**Examples:**\
Error: 0 : No credential Manager found\
Warning: 0 : Refreshing token failed\
sipgateFaxdrucker Critical: 0 : error loading credentials: The array must not be NULL
Error: "The operation is not supported on this platform"
**Analysis**: C://Users/"Name"/AppData/Local/sipgateFaxdrucker/Logs\
check for errors or send to sipgate support\
**Cause**:\
**Solution**:
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://help.sipgate.de/cloud-telefonanlage/en/using-sipgate/fax/faxdrucker-windows-fehler-und-loesungen.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.