8
Hi,
in XOOPS 2.x you can check version in include/version.p h p. Maybe in 1.x too...
First, before doing anything, better do a full backup of database and files.
/user.p h p is not rendering too, so you will not be able to enter. You may try to enable PHPDebug mude by entering the value in database. It is described in the link by Mamba.
I never upgraded a site from XOOPS 1.x (and never had one too, so I have no experience with that). If possible it will be a multistep process, as the latest XOOPS can upgrade from 2.0.7.x and newer. If you go this way, do a backup after every successful step.
You may check your provider - if they upgraded their PHP version recently, they may kept an option to use PHP4. With my provider I can set this in htaccess file, but this will vary with providers and may not be possible.