This is mind blowing...
That's the second time. I looked at the file before attaching it to this post and it was not blank. Now it's blank.
The two laptops share files via Sync.
I do not normally run the software from the shared drive (it causes issues with a bunch of apps) so each laptop has a local folder where I run the software from, then for backup, I copy the working folder to the Sync folder. When I want to run the same software on the other laptop, I copy from the Sync folder back to the other laptop's local drive.
This has worked for many many years. I do this with my C source code and B4J, and I was doing it with Visual Basic before that. I used Dropbox before Sync.
Well, I am working (and sending this message) from the "main" laptop now and this is the file...
This all started because I got a newer new laptop last Friday (so there are 3 at the moment, the main, the backup and the new), so I started the process of copying and installing everything on that new laptop and I thought I would check the old backup machine to make sure the process worked as I expected. That's when the problem started.
The good news is that the new laptop seems to be behaving normally, no issue with that file or with running the app once loaded on the phone (but a strange issue that I cannot load the app via USB on the new laptop, only with B4A Bridge. It's the same phone, same version of B4A and same Windows 10... But that's another issue.)
Anyhow, there seems to be a weird problem with Sync on the backup machine, so I am going to take it offline until I figure it out.
Sorry for the distraction. I'll update when I have something.