No characteristic value groupings are possible for characteristic &1

What causes this issue?

In order to group characteristic values, the characteristic in question
has to meet the following prerequisites:
The data type has to have format <LS>character format</>.
The maximum number of places is 18.
Function module WRF_CHECK_CHAR_VAL has to be specified in the <LS>Value
Check via Function Module</> group frame in the <LS>Values</> tab page.

System Response

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

How to fix this error?

Check the settings in characteristics management (transaction CT04).
Then call the characteristic value group function again.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.