App Lab - "we can’t figure out what background is " bug

Hey all,

One of my students is running into a bug for the “Make a Library Project”. Everything looks good, but when the program is ran it states an error with line 2:

“ERROR: Line: 2: Oops, we can’t figure out what background is - perhaps you meant the string “background” with quotes? If this is meant to be a variable, make sure you declared a variable: var background”

Link to project:

I’m stumped and would appreciate some help!


Nick Bahr

This is a strange issue that I haven’t seen pop up before.

I was able to remedy by simply copy/pasting the code into a new App Lab program, and re-linking the data source.


1 Like

The code has a library imported called HappyBirthday, the error is in the library. I think the library is actually Game Lab code that won’t work in AppLab.

That does look like gameLab code to me. Could the student remove it from the library, or take it out of the import?

Thanks for all the feedback everyone! Turns out that I had this student in a previous semester for the CS Discoveries course. She had shared her game with me at that point and for some reason was associating her old game project with her shared library. We unshared her game and then refreshed the library app and it’s all good now. Thanks again for your quick and thoughtful responses!