same here for nearly a month now.
raised Support ticket back in December and was told that Studio was aware of the issue, and should be resolved in patch 15, which obviously haven't worked.
Then patch 16, and still same issue
Was the bug present in release version?
Did it start occurring after one of the hotfixes?
Will physical copy have same issue?
The workaround, with cross saves doesn't work for me, or when it works, allows to Save once and then error 544 returns