Verify non-admin users run smoothly.
I have published Spark 2.5.5 via a GPO to a group of users. One of them installed the app, which was successfully installed, but when they tried to run it the egg timer appeared briefly but then immediately disappeared. I used RunAs to run it under my account but had the same problem, so then I used RunAs to run it under an Administrator account, whereupon it loaded successfully and once closed worked correctly for both myself and the other user.
This suggests to my mind that a file or registry entry is written upon first load that a standard user account does not have access to. Where abouts would this be, so I can change the permissions to allow anyone to launch the app?