As I am suffering from this bug as well I have updated my installation to Plesk 10.4.4 and installed any available micro updates:
Code:
/usr/local/psa/admin/sbin/autoinstaller --select-product-id plesk --select-release-current --reinstall-patch --install-component base
[...]
File downloading PSA_10.4.4/microupdates/MU7/common/panel/plib/backup/Conflicts/Resolver/ConflictsResolver.php: completed.
File downloading PSA_10.4.4/microupdates/MU7/common/panel/plib/backup/Conflicts/ConflictConstants.php: completed.
File downloading PSA_10.4.4/microupdates/MU7/common/panel/plib/backup/Conflicts/Detector/Limits/ClientBULimitsManager.php: completed.
File downloading PSA_10.4.4/microupdates/MU7/common/panel/plib/backup/Conflicts/Detector/Limits/BULimitsManager.php: completed.
[...]
But the error persits! Plesk panel is still counting subdomains towards license domain limit.
I can NOT confirm this bug being fixed in 10.4.4 MU7. Please fix as soon as possible!