I am seeing this error when saving a favourite (on catalina.out). The favourite is never saved. What can be the issue? It only happens when choosing ‘Details’ for data elements.
2.30 is an older version of DHIS2 is no longer supported. It is expected that you could face many bugs which are fixed in later versions of DHIS2. The best advice I could give you is to make a copy of your instance as a test instance and upgrade it to the latest versions and see if everything is working properly then upgrade your production instance.