Invalid Line URL detected for the user %1 (enabled for Pc-to-Pc Voice). Line URL for Pc-to-Pc voice enabled users must be ...

Invalid Line URL detected for the user %1 (enabled for Pc-to-Pc Voice). Line URL for Pc-to-Pc voice enabled users must be specified as a tel: uri. Otherwise functionality that depends on the Line URL for such users will be affected. Data will not be replicated until this problem is fixed.
Resolution:
Fix invalid Line URL.