We created a new Application in the customer's production environment, but the save ended with an error.
The log file is showing general error, according to which we can not determine the cause.
Release : 3.5
Component : API PORTAL
The issue was caused by a missing default API plan , the name of the default API plan (Sandbox), was changed.
After changing it back to the original name, everything started working again and new Application could be created .