Halo: The Master Chief Collection Message Board  

Done all of that, could not delete three files in the Temp folder:

~DF161E8D749B5A83CD.TMP
NGLClient_AcrobatDC112.0
qtsingleapp-icueex-80b4-1-lockfile

Still getting same error however:
17:14:21: HALO CE Anniversary, 03-03-2020 (STEAM/WINDOWSSTORE/XBOXGAMEPASS)
17:14:59: Successfully attached to MCC-Win64-Shipping
17:15:00: Collect Player, Script error in line 12: Cannot find aob for 'Collect_Player'

Downloaded the ODST trainer and it activated with zero issues. Went back, redid everything and redownloaded Halo CE trainer a third time, same error when trying to launch via F1 or manual.

Just thought I would check to see if this was somehow linked to the achievements being borked. While using that enabler did finally unlock my "Goat Roaped" achievement, unfortunately, it still had the same error launching the CE trainer:

16:28:13: HALO CE Anniversary, 03-03-2020 (STEAM/WINDOWSSTORE/XBOXGAMEPASS)
16:28:39: Successfully attached to MCC-Win64-Shipping
16:28:39: Collect Player, Script error in line 12: Cannot find aob for 'Collect_Player'

Separate issue

Please use the update notification system to report a game patch, update or to report that the trainer may not be working with the latest version of the game. If 3 or more reports have been filed, consider BOOSTING the priority of this title for a faster turnaround on the updated trainer.