Fax number to be replaced has an incorrect format

What causes this issue?

The fax number you specified to be used &V1& is not in canonical
format. The fax number check is switched on.

System Response

The configuration was not adopted.

How to fix this error?

You can adapt the number to simple canonical format:
Permitted characters: 0123456789() and space
Format a) '(Dialing code) number', e.g. '(06227) 344348'
Format b) 'Number', e.g. '4348'
Format c) Not filled
Alternatively, you can switch off the fax number check in SAPconnect
Administration.

Error message extract from SAP system. Copyright SAP SE.