I had a similar problem when exporting a ZIP file for posting, using the Export as ZIP feature of B4A. In addition to the xxx.b4a files and a xxx.bas file, there are three folders in the project. These are Files, Objects and addres. Although the folder addres appeared in the prep window, it was not include in the ZIP file. I then had to insert this folder into the ZIP file manually, prior to posting. There absolutely is a problem with the Export feature, and this likely what LucyC experienced.
Regards