Missing TABLE_ID_GENERATOR in SDE

[Meroni]

Hi, I am trying to create a feature class and schemaBuilder.Build() yields the following error:

CreateAnnotationFeatureClass
test_t
Error: The table already exists.

However, there is no table test_t in the SDE. After researching a bit I stumbled upon the following link https://support.esri.com/en/technical-article/000006563 . The workaround should solve the problem (at least that is what I believe). The problem is that the SDE has no sequences and the workaround mentions that I have to call  

SELECT last_number FROM user_sequences WHERE sequence_name = 'TABLE_ID_GENERATOR'; 

However, since there are no sequences I can't even complete the first step of the workaround.

Question is, why are there no sequences in my SDE? 

[Aashis]

Probably the DBMS is caching some information about the feature class.

I would begin troubleshooting by manually removing the entry of the feature class from the GDB_ITEMS table and then recreate it.