I am experiencing an issue installing MyBB on my InfinityFree hosting account.
The MyBB installer starts correctly, and the requirements check passes.
However, when I reach the database configuration step and click “Next”, the installer always returns a 500 Internal Server Error.
Important details:
The 500 error occurs even when entering intentionally incorrect MySQL credentials
This suggests the failure happens before actual database validation
Other applications install successfully on the same account:
WordPress
Joomla
Drupal
phpBB
SMF
I also manually renamed inc/config.default.php to config.php as required, so this is not a file permission issue.
It appears that the MyBB installer process may be blocked by server-side security rules (possibly WAF/mod_security), while other forum software is not affected.
Could you please confirm:
Whether MyBB is known to be incompatible with your hosting environment, or
If there are any server-side restrictions that could cause this behavior?
I can provide screenshots of the installer steps and the error page if needed.
We don’t have extensive mod_security rules on our hosting (too high risk of false positives). And requests that are blocked will get a clear 403 Forbidden response, not an 500 Internal Server Error.
I’m not aware of any compatibility issues between our hosting and MyBB.
Or the issue only happens if your database credentials are incorrect, and you were just entering incorrect details even when you thought you were entering correct ones.
To fix this, I can suggest two approaches.
The first is to try stop speculating about the 500 error and instead try and get more information about it. An actual PHP error message would help a lot in figuring this out.
The second option is to skip installing MyBB manually entirely and just install it with Softaculous. Softaculous offers MyBB and can handle the installation for you.