We've just updated our 3 Moodle instances to 3.5.1+. Two instances were on Moodle 3.1.6 and the other one was on Moodle 2.8.
After upgrading the 2 instances which were on Moodle 3.1.6, we're encountering the error:
'Coding error detected, it must be fixed by a programmer: Cannot find file with external function implementation', when trying to access the API documentation and the web service test client.
The other Moodle instance, which was initially on Moodle 2.8 is working fine.
We have tried purging all caches but the error is still displayed.
Your help in this matter is greatly appreciated.