For some objects following error occurs on the Identifiers, Table Usages and Column Usages tab:

The obvious reason is that the sys_connect_by_path function produces a result with more than 4000 bytes. This can happen only with more or less 130 levels (assuming a max of 30 characters per name). In a customer's case there are more than 700 levels. Most levels were artificial. Produced by the fix of inconsistent PL/Scope data (missing levels). In such a case the node was connected to the last previous consistent node. In case of a series of calls to a unit which is not compiled with PL/Scope this leads to a lot of nested levels where no nesting would be expected.