Web API downloads/categories end point failing

[Interferon]

Although other end points are working, this end point does not:

https://www.xxxxxxx.com/community/api/downloads/categories?key=xxxxxxxxxxxxxxxxxxxx

This is the result:

{
    "errorCode": "EX0",
    "errorMessage": "UNKNOWN_ERROR"
}

Permissions for the end point for this key are enabled. All other end points I have tested worked as expected, including downloads/categories/{id}

Invision Community v4.7.5

Edited June 8 by Interferon

[Daniel F]

Do you see any logged errors in your system log?