Anything that prevents you from playing the game properly. Do you have issues playing for the game, downloading it or successfully running it on your computer? Let us know here.
otherway the only possiblity may be to identfy the not working mods and fix them manualy. (deaktivate one mod at a time and see if the error shows up. If not the reaktivate it with handmade corrections).
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if you have identified the faulty mod I will look into a possible solution. PM me with the faulty mods.
This is a know bug with the error window. You can find the complete message in the factorio log. But this really is a problem with a mod, most probably the mod needs to be updated to the new naming scheme ( https://forums.factorio.com/forum/vie ... =14&t=5364 ).