Error in buffer: update failed (&1, &2)

What causes this issue?

An error occurred when the system updated data stored in the buffer.

System Response

The system did not save the data.

How to fix this error?

Notify your system administrator.
The table in which the error occurred is specified in parentheses. You
are also informed of the activity during which the error occurred.
Here, the following letters have the following meanings:
I: Insert
U: Change
D: Delete

Error message extract from SAP system. Copyright SAP SE.