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?
Have you added the Rex plugins you are using in your old projects into C3 using the updated C3 versions of the addons?
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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.