On attempt to modify a record of domain with assigned hosting - Apache, QMail, etc - in CCPv2, the following error message is displayed:
You can't modify record 'record.provider.tld'. It's used by another service
In CCPv1/PCP this record has "System" type, it was created automatically by hosting service.
CCPv1 does not allow to modify record's properties, but CCPv2 has an "Edit" button for "System" type of records, however this type of modification is still prohibited. A request to remove this misleading button was submitted to Engineering team as PFR-842.
Currently there are no workaround and it is not possible to upload customized DH group. Please contact your Technical Manager or a member of Pooled Technical Associates team in order to clarify its status.