Chat issue on Nostalrius 7.7

[bilexar]

Hello, I'm an inexperienced programmer and I'm trying to run the nostalrius 7.7 here on my windows. Everything is OK except for this: whenever I type regional letters (Like ç) on the game chat and send the message, this error occurs and then the server closes:

Debug Assertion Failed!

Program: ...s\user\otserv\Nostalrius-master\theforgottenserver.exe
File: minkernel\crts\ucrt\src\appcrt\convert\isctype.cpp
Line: 36

Expression: c >= -1 && c <= 255

For information on how your program can cause an assertion failure, see the Visual C++ documentation on asserts.

(Press Retry to debug the application)

What can I do to fix it?

 

[LordCompi]

add somewhere there c &= 0xFF; should set c to byte