Profile installation Failed
It's good to hear you've found a solution you felt acceptable.
The reason I asked about your previous MobiControl version(s) is that, according to MobiControl set-up guide, MobiControl v14.x is not officially supported for Windows 2008R2. You should have upgraded the Operating System to at least MS Windows Server 2012R2 if you upgrade from MobiControl v13 or earlier. If your very first implementation was already v14.x, you should also have chosen at least MS Windows Server 2012R2 back then.
We were running 14.1.x previously (can't recall the last digits). The phones didn't work on that version either, was getting the same error as https://discussions.soti.net/thread/ios-12-devices-fail-to-enroll-with-error-profile-installation-failed-a-network-error-occurred/
-- EDIT - FIXED!--
After much mucking around I came up with the following solution;
- Put the devices into DFU mode
- Using iTunes, install the latest iOS 12 update
- Remove the devices from their profile in MobiControl, and re-add them
- Ensure that the SSL cert is using the appropriate cipher for Apple devices. Redeploy the certs into IIS and mobicontrol where needed
- Increase the maximum query request size from 2048 to 8192 (this seemed to fix the SCEP failure)
- Patch Poodle attack (this seemed to be the deciding factor for us, after this everything started working)
- Reboot each device and go through the installation
What was your MobiControl server version before your recent upgrade to v220.127.116.1194?