This happened with me once and thankfully @Conor helped me with it.
It seems you removed an extension (Infinite Progress Bars) and it can’t find it, readd the extension, remove all blocks dealing with it (or components), then delete the extension.
I have a solution
Export the aia and then open it in winrar and then open assets
then open external_comps
and delete the extension you want.
This will help and then just leave it as it is after deleting and then delete project from kodular and
import the aia you exported and edited.
It works everytime