Are you using a tool like Microsoft OneDrive? If you are, then try moving your project out of OneDrive to another location. Tools like OneDrive try to sync your files but this can cause issues if Mendix is still trying to use and update it.
If you aren’t using OneDrive, do you have any antivirus software that carries out real-time scanning of files? That could cause the same problem.
Hope this helps and you get your project built.
Hi David,
Clean the deployment directory and then try deploying again