Upgrade problem

Hi !

I have a strange issue on my site :
I have an existing website, with several pages an so on, that was built on Revo 2.0.0 Beta-3 rev 5853.
I am trying to upgrade it to 2.1.15. Upgrade process works fine, some warnings but nothing new here. I can log to the manager alright.
The trouble is when I try to access the frontend, or to do anything with pages in backend (view, edit, create) => I always end on an empty page.
I tried reinstalling several times, loading again the zip package, flushing cache... I can't find any way to make it work.

Anybody has any idea to make it work ?

I do all these test on a local installation using UwAmp 2.1, with PHP 5.2.17 and mysql 5.5.9.

Try manually deleting all files in the core/cache directory and clearing your browser cache and cookies if you haven't already.

I did, and it doesn't change anything.
I can edit and view anything under the "elements" and "file" tabs, but trying to access anything under the "ressource" tab gives me a blank page, and nothing in the error log

I also tried installing Revo 2.2 RC1, and the problem is still here... I really don't know how to pinpoint the root cause of the problem...
I can view ressource informations, and access to the quick modification, but I can't access the standard modification or create a new ressource -> I always end on an empty page (really empty, 0 byte, nothing, not even a single char...)
Any idea how to solve this ?

I'm sorry, I don't. I can't think of anything that would cause that. Maybe someone else will have an idea.