UCT8037 - Mapping rule for &1, row &2: MOVE is incorrect

SAP Error Message - Details

• Message type: E = Error

• Message class: UCT8 - Message class for UCT8(mapping)

• Message number: 037

• Message text: Mapping rule for &1, row &2: MOVE is incorrect

What causes this issue?

For each source field of an operator you can split the source into two
pairs of attributes: offset and length; separator and index.
The current values are invalid because they do not meet the following
requirements:
Offset and Length
When an "offset" is defined without a "length", the move operation is
valid. The system moves the part of the character string starting at the
offset position up to the end of the string.
When a "length" is defined without an "offset", the move operation is
valid. The system moves the part of the character string starting at the
first character up to the position designated by the "length" to the
target field.
When a value is specified for the "offset" or the "length" (or both),
then the "separator" and the "index" may not have any values. Otherwise,
the move operation is invalid.
The values must be numbers greater than zero.
Separator and Index
Both the "separator" and the "index" must contain values. The move
operation is invalid if only one of the attributes contains a value.
When the "separator" and the "index" contain values, you may not enter
values for the "offset" and "length". Otherwise, the move operation is
invalid.
The value for "index" must be a number greater than zero.

System Response

The settings will not be saved.

How to fix this error?

Check that your settings meet the aforementioned requirements and adjust
your settings accordingly.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.