No problem.
The "persons.db" file is in the Shared Files folder of the cross-platform project.
All common files should be saved in this folder and when you run the project in any platform these files are copied into the platform specific Files folder.
This is done by the first line on top of the B4XMainPage module.
#CustomBuildAction: folders ready, %WINDIR%\System32\Robocopy.exe,"..\..\Shared Files" "..\Files"
Be aware to keep the B4XPages project structure when you transmit any B4XPages project.
The zip file you posted, ziped with IDE menu, is no more a cross-platform project because the Shared Files folder is missing.
To make your project run, I had to comment the first line.
I have now updated the original B4XPagesSQLiteLight2 project with this line:
'Ctrl + click to export as zip: ide://run?File=%B4X%\Zipper.jar&Args=Project.zip
Which allows to zip the complete P4XPages project.
This line was missing, I wrote this project before Erel added the method above and forgot to update it.
Attached the new original cross-platform project.