I have just installed b4a 3.80 and was trying out a few new libraries. Then I suddenly got this error message on loading a new project "Basic4Android: An error occured. List box contains too many items".
I thought it was in the project but it appears to be a bug in the ide. It seems easy to recreate:
Load b4a.
Load a project where you do not have the additional library (or move a library out of the directory).
It will generate the error that the library is missing but the project will load.
Open explorer and copy the missing library back into the correct directory
Re-open the same project.
Bang! Error as above and all the libraries in the tab lib are gone.
Restarting b4a corrects everything.
I know there is a refresh command on the right hand mouse, this works of course and normally no one would do what I just did.