Hi @MitDenukN,

The most common cause of this Oracle error occurs when you attempt to execute an operation of two different data types that are incompatible. 

In addition, it may have occurred because the user tried to perform an operation on a database object that is not intended for normal use.

Can you try to disable any configurations associated with this screen including custom fields and custom events for that logical unit. 

If this is issue cannot be recreated for IFSAPP, please try to restore the user profile and base profile for that particular user.

Regards

Manoj

Hi @Manoj Ruwanhewa , Thank you very much for your opinion.
I could recreate the error with IFSAPP for the same record when I try to approve. But when I create another absence request from a different user and try to approve it with IFSAPP, I was able to approve it without any error. However I will try all your suggestions.
Thanks again 

Hi @Manoj Ruwanhewa, I have created a absence request for the same user by logged in as IFSAPP.
Then I was able to approve the request, without errors. There are custom fields in the header of My Absence Calendar window but there are no custom fields in line level. Those custom fields working fine for other users as well. So do I still need to worry about the custom fields. 
 

Hi @Manoj Ruwanhewa , finally we could solve the issue. The user has manually inserted ‘Annual’ for On Demand Absence Type ID even though LOV doesn’t contain any data for this field. When we remove those values from her records, we were able to approve records without any errors.

Thank you so much @Manoj Ruwanhewa