This is unrelated to the Q2A core itself. I believe it is one of the following issues:
Just install a new clean Q2A version in your server and it should work fine. If it doesn't, I guess you should blame the server.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.