Hi ,
Please check the SPAU and the SPDD object that is related to the above process and has been reset to original by the Basis and the Technical team.
If you find any object please retrofit it for your functionality to work.
I might be that you would have customised any standard sap code and that sap would have provided the fix and got poped up in SPAU and SPDD and got reverted to standard code..
Please check the below note.
1690429 - Error message KI235 is issued in transaction code FB08
1881464 - Error KI235 when post IDOC coming from SD billing output
Thanks
Rishi Abrol