Stopping a plugin activating

Hi,

I am currently developing a new version of a plug-in. Essentially, I want to detect any previous versions of the plug-in in instance, and if there are any, stop the current version from activating.

I expected there to be a hook on activate_plugin or validate_plugin for which I could trigger an error, but there doesn’t seem to be one. I tried outputting text, and get a fatal error, but the plugin is still activated. I’m sure there should be a feature to do this easily, but can’t seem to find it.

Please let me know if you have a solution…

Thanks,
Brendon.