Forms are not responsive. Reference field popup, right click on the header, UI macros and changing sections does not work. Tailing the node logs while accessing the broken form displays the following error:
2018-10-11 10:18:42 (294) Default-thread-11 0B2E09D6138D6B007F67D0528144B09A txid=15e0151e138d SEVERE * ERROR * null:3874:995: <g2:list_record_relationship> GlideRecord.setTableName - empty table name
This is caused due a relationship on the form with a missing table. The relationship is usually part of a section as a section element. If you are seeing this issue on change request form and the relationship is as follows:
This section comes from "Change Management - Collision detector" plugin that can be missing in Express to Enterprise converted instances.
Delete the relationship which is a form section element from the affected form. Clear the instance cache by typing cache.do in the application navigator as an admin. This should resolve the issue.