Server Crash:repeatedly flashing „Connection Lost“ on web interface. Server function not recoverable

Hi guys,

I purchased Repetier-Server about a month ago and have been very impressed by the functionality, it is simply an incredible software that is a must for multiple printer environments.

Our setup is as such:

-RS Pro (V6 SD Image 0.80.3 for Raspberry Pi

- Raspberry Pi 3

- Official Raspberry Pi 2.5A Power Supply

-7” Official Raspberry Pi Touchscreen attached to Pi DSI port via ribbon cable

- Connected are 2 Reprap Printers, RAMPS 1.4 + Arduino, both running Repetier Firmware

-The connection of the Raspberry is through WLAN, not Ethernet.

The Problem:

A Week ago the we turned the Pi on, opened the web interface on a wifi connected laptop, and immediately the web interface began flashing very quickly and repeatedly “connection lost”. Almost seemed to rapidly cycle between the usual connected Server interface, and the connection lost error. On the 7” touchscreen control the touchscreen interface started up but the settings for multiple extruders and heated bed were absent from the Parameters and the printers could not be controlled any longer via touchscreen.

Restarting the Raspberry pi through “reboot server” and also pulling the power plug did not change the error. I reformatted the SD card and reinstalled RS-Pro with the same, and most current version.

This morning by starting up Repetier Server the same exact “Connection Lost” flashing.

Can anyone help out?Is this a known problem? Is there a way to resolve this error via SSH (I am somewhat Linux proficient) where I don’t have to reinstall the Server on the SD and repeat the setup procedure for both printers?

Thanks and freundliche Grüße,



  • I just had an other user with the same problem. He somehow managed to upload a file with non UTF-8 Filename. When you then connect the browser sees this non UTF-8 character and disconnects - server then reconnects so you get the flashing.

    Solution is to delete the file with non-utf8 filename on pi. SO login with ssh and go to /var/lib/Repetier-Server/printer/<printerslug name>/models and check directory with ls. Since they are sorted by id the last files appear last and one of these is probably the problem. In my test case it was a "ü" that become ? in ssh. Delete all files with same id at the beginning and restart server and you should be able to connect again.

    For next release I have added a filter to check filenames.
  • Bingo, that was it. Actually we had a double whammy....had a "ä" AND the degree Symbol "°" which were uploaded in the name. Both were causing the Problems.

    Thanks very much for the great support!


  • For 0.85 we have added a detection and replace these chars by _ so nothing bad happens.
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