I installed the Twitter addon, and my backend went to:
0 Class 'JFBConnectProviderPlugin' not found
This was a hard crash. I had to manually remove the entire plugin directory to recover the site. Setting 'enabled' in the extensions table to 0 didn't disable it. Front end threw a 500 on template load.
I installed the addon after realizing that the floating social share wasn't firing 'ready' on the twitter object in the javascript (undefined object). Seemed to me that it was missing because the addon hadn't been installed.
But installing... boom.
1. Boom. As I said
2. I think you guys REALLY need to put some SERIOUS checking each and every place you expect to have a plugin enabled. The social share module was happy to let me display a twitter button even though the plugin wasn't installed.
3. Boom. Yeah, I know, I said boom already, but I thought it was important enough to say again.