We have a multi store Magento installation that we moved from a VPS to a dedicated ubuntu server.
We just copied the files and transfered the database to the new server via HeidiSQL export tool.
Everything seemed to work fine, expect now we discover that the Up-sells and Associated Product tabs aren't working properly. I clicked them, it displays the "Please wait" loading screen as usual, but it just stays in the same place. Not even the url changes.
These are the two tabs we actually use, the rest of the tabs work fine. I'm sure it's not a coincidence as it's exactly the two tabs that have data in them, so I'm guessing there must be some kind of conflict.
Question is, how can I debug it? Or does anyone know what's wrong with it?
Turns out it was a Php compability issue. The new server had a different version. Installed the same version I had on my VPS and it worked after that.