Android Question [SOLVED] "class not found" even when it´s checked in libraries


Licensed User

In short what I made:
  1. I studied and altered the sample project of xCustomListView to insert this code as a second activity into my own project. For altering I used code from this question: to call the activity and get values back.
  2. I copied the .bal-files into my project and opened them in designer.
  3. For the 2nd activity itself I added a new one (project/add module/new activity) and copied the code from the sample project to my new 2nd activity. (I had to remove the "project attributes".)
  4. In both projects (mine and the xCustomListView) was the xCustomListView-library already checked before.
Now what B4A says, when the 2nd activity is starting:

Is there an easy way to get rid of this error?

The library is loaded, so I see no reason why the 2nd activity tries to find the library at an other path/origin?

I would also like to submit the project as a zip-file, but strangely after asking for the name of the zip (to create) b4a doesn´t create the file. It even overwrites an old zip with nothing, means it deletes it in fact.
So I packed the project folder with windows into a zip-file instead and deleted the objects-folder because of the size for uploading...

Any idea?
Thank you in advance!


  • 2018-09-04 14_51_36-TeacherApp - B4A.png
    2018-09-04 14_51_36-TeacherApp - B4A.png
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Licensed User
Forgot to show:
2018-09-04 15_55_58-TeacherApp - B4A.png

Are the references to certain libraries for different activities different ones?
I always thought the libs are for the whole project the same... aren´t they?
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Licensed User
Longtime User
Is there an easy way to get rid of this error?
you are using a layout from another app-package.

Open the layout, remove the CLV. Add it again. Save layout. The CLV is now linked to your app package.

Try again...
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Licensed User
@Erel: Ok, I will do that in future.

@DonManfred: Thank you, that was the solution!

So obviously this is necessary with all custom views which were added in other versions, say B4J instead of B4A...
Good to know!
Thanks a lot!
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