RESTACTION error in Learning Outcome Page

Summary:

We are getting the REST ACTION error in the learning outcome creation page.
Navigation - My Client Group>learning>Courses>Manage (under skills and qualification, general information).

Error is received and also the dropdown don't show the item catalog list. Please note this is not working for some 90 courses, for the rest of the courses this is working fine for the same user.

There is no role issue here, since its working fine for majority of courses for the same learn admin user.
These 90 courses only difference is the learning outcomes were loaded via HDL, the load was success, but still the outcomes don't show in UI. This is another issue.