OBIEE 11g Writeback error while updating

Hi All, I have a writeback request where I need to update columnA(Date), columnB(date), COlumnC(text)  in a table based on integration_id column. All columns are Nullable.

I implemented the following statements in Insert and update tags.

<insert>Update my_table set columnA = TO_DATE('@{columnAid}','MM/DD/YYYY'), ColumnB= TO_DATE('@{columnBid}','MM/DD/YYYY'), columnc = NVL('@{columncid}',' ') WHERE integration_id = 'xxxxx'</insert>

<update>Update my_table set columnA = TO_DATE('@{columnAid}','MM/DD/YYYY'), ColumnB= TO_DATE('@{columnBid}','MM/DD/YYYY'), columnc = NVL('@{columncid}',' ') WHERE integration_id = 'xxxxx'</update>

but here is the issue -

I am able to update few columns for the first time, but when I try to change any particular column value in that very updated row, it is throwing an error.

For eg; I logged in, updated column A, Column C and saved the data without any errors.

Next time I logged in and tried to update column B or change value in ColumnC for that same record, It is throwing error

I am getting same error even when I try to change values in any column;  even when none of Column A/B/C are null.

Write Back Error

An error occurred while writing to the server. Please check to make sure you have entered appropriate values. If the problem persists, contact your system administrator

Please advise.

Message was edited by: user8840662