500 Error When Trying to Use API to Create Issue

One of my team members sent ahead an issue they ran into, that I'm not familiar with, and wasn't sure on how to approach troubleshooting:

I'm running into API issues that I haven't dealt with before. I am getting a 500 error. This is the error that I am getting:

{
"ID": 795073923,
"Message": "An error occurred. Please try again, and contact TeamDynamix support and reference the Error ID if the problem persists."
}

I am trying to do a POST to:
https://umdearborn.teamdynamix.com/SBTDWebApi/api/projects/issues?NotifyOnClosed=False

with the payload of:
{
"PriorityID": 1,
"Title": "SI-02 FLAW REMEDIATION",
"StatusID": 24066,
"CategoryID": 479780,
"ProjectID": 402217,
"Description": "...."
}
 

Would anyone be able to provide a bit of insight here?