Thread:Project:Support desk/HTTP 500 problem when trying to access mediawiki/reply (6)

Be sure c:/Bitnami/ is writable by the webserver. You may want to create a new folder just for the logs and allow the pseudo-account "Everyone" full rights.

If you still get the 500 error and no exception detail is shown, you can also try to set  in php.ini as explained on the how to debug file.