I do agree it's quite strange. I can compile and install but this error only comes up if I exit B4A and start B4A up again by selecting the app project.
Maybe B4A did not clean up some Java files or something like that.
As a side note, the file it sais it can't find is from an older version of the app that the designer referenced but I deleted that image file using the designer and also made sure it was not listed in the files tab.
Edit your .b4a file using Notepad and search for: "NumberOfFiles=" right under that you will see the files that are part of your app, you might see the one you deleted, you can remove it from the list and save.
Make sure you backup that .b4a file before messing with it.