RAK7289V2 Firmwareupgrade doesn't work

I tried to make a firmwareupgrade from OS 2.1.7 to the latest Version WisGateOS 2.2.6
After about 15% Upgrade, I get message “internal Server Error”
I did the process multiple, always the same problem
Whats on?
thank you for a feedback

Please include the following information, in order for us to help you as effectively as possible.

  • What product do you wish to discuss? RAK7289V2

  • What firmware are you using? WisGateOS_2.1.7_RAK

  • What firmware version? Can it be obtained with AT+VER=?

  • Computer OS? (MacOS, Linux, Windows) Windows

  • What Computer OS version? Win11

  • How often does the problem happen? always

  • How can we replicate the problem? Yes

  • Provide source code if custom firmware is used or link to example if RAKwireless example code is used.