I can't open any of my old C3 projects because apparently some of the addons I've been using since getting C3 are now "not found". Is it just me or is this a common occurrence?
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Have you added the Rex plugins you are using in your old projects into C3 using the updated C3 versions of the addons?
wouldn't use any of Rex's plugins. They aren't going to be compatible with the new runtime. They will need to be rewritten and he isn't going to do it.