Application builds successfully but can not run

Hi

Just having a problem with Unity and building the application. The build pipeline completes and has the _data file, .exe etc in the build application folder. The .exe is only 1kb in size and will not run. After rolling back to the previous push on source control it builds and is able to be run.

Bringing the application back to the latest push in and undo all the changes that were done that push (only a couple of minor script changes) the build no longer runs and returns to 1kb in size.

Has anyone experienced this before and if so any ideas on how to fix it? the build is windows 64