I have a very old version of Tasker I use to create apps for an e-ink reader running Android 2.1 (Eclair). After a recent (security) update to the OS, I found I could not install Tasker unless I resigned it.
This worked OK except that apps which function as plugins would not work in tasks (although they do work if the tasks are compiled as apps with App Factory). This makes debugging very tiresome. I've tried resigning the apps used a plugins with the same key to no effect.
Based on my reading this might be an issue with "shared user ID", but I don't know where to go from here to see if there might be a "fix".