I have this problem at home on windows 11 since some days.
I'have seen many post here proposing solutions but I was not able to solve the problem. I've try so far:
Disable Antivirus.
Run B4A in admin mode.
Move the project directly to C:
I also tried a solution like that to give full access to the folder
Nothing works to date. I don't really know what to do to make it work on windows 11. Luckily I have a laptop running windows 10 that I can use.
It is not related to the Windows version.
Something is locking a project file. Restarting the PC will solve it.
Does this issue return after a restart?