I got this problem after install
A Question2Answer database query failed when generating this page.
A full description of the failure is available in the web server's error log file.
If you send me your error log I will be able to fix it.
however there is an action which might solve your issue:
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.