Re: Errors and need to upgrade, but...
My guess is that your host has made changes that have confused your site.
It sounds like your filepath or database settings have changed due to some upgrade your host has done so now they are not correct and it is "crashing" your site.
If this is the case then you should be able to adjust the file paths and/or database settings in your mainfiles.php to reflect the new settings.
Your best bet is to do the following...
Backup both your database and files.
Install xampp or similar program on a local computer.
Install a copy of your backed up database to you local computer.
Copy the files into the proper area on your local computer.
You will then need to edit your mainfiles.php to reflect the correct pathnames and any difference for the database.
This allows you to have a local copy to mess around with and get working before trying to get your live copy working.
You may be able to use an old xampp (or similar) version to access your site and get it running. Depending on what you are trying to accomplish. If all you are trying to do is access information on the site this may be your most simple solution assuming no one has messed with files on the site.
Assuming you need to continue then you are going to want to do some work before you attempt your upgrade.
Get into the database and in your "modules" table there is an entry called "isactive". You want to change this field to 0 for every one of your modules EXCEPT system. This will disable all of your modules so they don't automatically run when you are completed with your upgrade.
You should then upgrade to either 2.4.5 before you try 2.5.4 or go straight to 2.5.4. Some modules will break under 2.5.4 that work fine with 2.4.5 so that is your choice. The latest version of xoops should be the most secure.
You are performing this upgrade on your local computer to verify it will work before attempting on your live site. You can do all the work on your local computer then copy the database and files back to the live site once working. Or at a minimum work out your upgrade plan locally before attempting on your live site.
At this point you are ready to perform the version upgrade of xoops. Just follow the directions for whatever version you are upgrading to.
Test your site after this upgrade and see if it works. You will need to go to your module admin and "update" your system module.
Assuming everything works at this point you can then go to each module and "update" them from the module admin. This will ensure the database is insync with the modules with the upgraded install.
Once all the modules are updated you can enable them one by one to ensure they work with the version of xoops you are running. This will prevent you from getting the "white screen of death" and not knowing what caused it.
If you are getting the "white screen of death" prior to enabling the modules this means there is something wrong with your base install and you will need to fix that before attempting to enable any of your modules. Remember that the system module has to be enabled at all times in order for the system to work so do not disable this in the database.
Assuming your upgrade went ok and you have the white screen prior to enabling the modules you will want to make sure all the cache directories have been cleared, the sessions table has no records in it and the writable files are writable. If your upgrade went OK this should have already been done for you.
Another location to check for issues with the base install prior to enabling the modules would be your theme. You may want to use another theme temporarily if you still have issues. Use one you know works with the version of Xoops you install. (The included default ones are good enough)
Assuming all of this works but you get the white screen with one or more of your modules you are well on your way. When you find incompatibilities with the modules you will want to look for an update to those modules for your system. A lot of times those newer modules will work and allow you to migrate your data as well. Otherwise you will have to find newer modules that are compatible and import the data to those modules. Hopefully the new module has a script to do this for you otherwise it will require some manual moving of the data.
Hopefully this is a big help for you...
With older modules sometimes there are simple fixes but the easiest one is to upgrade to a newer version.
You will want to backup your database and files between steps once you have things working as you want. This will prevent you from having to start back from scratch if one of your steps doesn't end well.
Attending College working towards Bachelors in Software Engineering and Network Security.