@Michidu Thank you for taking the time to reply.
I have double checked spawning dino's from the console INSTEAD of through Tebex and it is working just fine. Vanilla or Mod dino's, with both GMSummon and SpawnDino. No crashes occur when spawning dino's in-game through the console as an admin.
I should probably clarify that the above error message was not caused by spawning any dino. The above error was caused by using the command "RainCritters". There's no specific reason for me to use this command, other than to simply test. There were more commands that crashed the server and I think we can both agree that any command should work when executed through Tebex or not.
Can I test anything else for you or provide other information?