Error Fetching Data!

Summary:

Trying to create a new rule for a new Configuration attribute results in the error "Error Fetching Data!"

Content (please ensure you mask any confidential information):

After creating a brand new Integer attribute and setting its properties, then switching to the Related Rules tab and trying to create a new rule, an error is displayed:

Error Fetching Data!

readyState: 4

status: 500

headers: cache-control: no-store
connection: keep-alive
content-encoding: gzip
content-length: 254
content-type: text/html; charset=UTF-8
date: Wed, 17 Apr 2024 15:10:14 GMT
expires: Thu, 01 Jan 1970 00:00:00 GMT
pragma: no-cache

vary: Accept-Encoding, User-Agent

As usual, no references to anything similar to this in the documentation. What does this mean?