I'm trying to update an old site that is still running on Craft 2.2 (from September 2014), but unfortunately the update process to the current version (2.6) breaks.
Does anyone have any experience of upgrading a Craft site from several versions back? I'm thinking my best bet might be to try doing it in a series of steps by downloading intermediate versions from here. I'm wondering though if there are particular version numbers that are good milestones for updating (or best avoided)? (I half remember a version that had to be manually installed a while back) Or alternatively, whether there's a better approach I haven't thought of?
Update: the problematic step seems to be upgrading to 2.5. I've managed to run updates up to the last build of 2.4 but the jump from 2.4 to 2.5 always seems to fail. The error message is just "There was a problem updating your database", so it's hard to know what exactly is going wrong.