Hello Nader;
As you have already confirmed that the table is empty, yes you can drop the index.
Please post the output of the SQL I gave you in the earlier reply anyway. Just curious to see which index the fields are part of.
I'd also do a "where used" check of the fields in your production system to see if other tables may be impacted by the DDIC change.
The above will get you moving forward and then SAP can tell you why this is occurring.
Close out this thread if you are happy with the answer(s).
Good luck.
Amerjit