Why is Jetty returning 403 on some PCs?

Question

Java

Good day.
I'm developing a distributed peer-to-peer network and I've come across the following issue. The project uses Jetty (the settings are written in classes, not in web.xml) and the output is a jar that does all the dark things. For some unknown reason, the assembly, which works fine for other users, returns 403 for one of the users

Answer 1

The user launches the jar and after working with the database, the ONLY html page on the project opens. Those. there is no question of forgetting the password.

Answer 2

What do the logs say?