Data entered in user fields could be lost

What causes this issue?

You have entered a different field key.

System Response

The system will offer other user-defined fields and/or change the field
labels, depending on the definition of the field key in Customizing.
Warning! All data entered in a user-defined field is lost, if the field
is not contained in the new field key.

How to fix this error?

Check the field key in Customizing for routings in
<DS:SIMG.SIMG_CFMENUOLPSOPEC>Operation Data -> Define User Fields
</> and take note of the warning above.

Error message extract from SAP system. Copyright SAP SE.