.htaccess Redirect causes Internal Server Error

Question

.htaccess

Redirect /index2.html http://example.com/index.html

causes the following error

Internal Server Error
The server encountered an internal error or misconfiguration 
and was unable to complete your request.

I think syntax of Redirect in this .htaccess is correct because this .htaccess works on another server.
What is the cause of this error?

Answer 1

The only thing I've found that reliably causes this type of error is when mod_alias (aka alias_module) isn't loaded for some reason. It's usually loaded by default, but could be disabled by the administrator.

You could check whether that's the case by changing your .htaccess to:

<IfModule alias_module>
    Redirect /index2.html http://example.com/index.html
</IfModule>

If you don't get the error, then mod_alias is not loaded, so the Redirect directive is unavailable.

If you still get the error, then it's something else. Realistically, you'd need the error log to see what happened.