Oracle is providing the diagnostic "ORA-00904 ; Invalid identifier" for an identifier which clearly does exist.
Thanks for reporting that but you need to report it to Oracle. Open an SOR to report it.
However, just on the off chance that it is actually YOUR code that has the problem, and not Oracle's code, why don't you post the actual code and a copy of the sql*plus session you are using to execute that code.
It is Oracle and not my code ; yes I have a screen shot of it - where do I post it ?
Your MOS support page has a link you can use to open an SOR.
But the problem is most likely in YOUR code; possibly due to a scoping issue where YOU can see the identifier but it is not in scope for the section of code trying to reference it.
This is the SQL Developer forum and, as the title says, is NOT for general SQL or PL/SQL questions. Nothing you have posted so far indicates any issue or problem with sql developer. So if you want help you should mark this thread ANSWERED and repost in the SQL and PL/SQL forum.
When you post there you need to provide ALL of the information needed to help you as I said in my last reply
post the actual code and a copy of the sql*plus session you are using to execute that code.
You can't post screen shots. in the forums.
Let us see your code.
Though Oracle does have bugs, in 99.99% of cases it is the user's code that is at fault due to misunderstanding etc.
I have been coding PL/SQL for a long time now and I always assume it is my fault first when something weird happens.
Only after very careful experimentation, reading of docs and asking my peers do I consider raising a bug report.