Unless you kept a backup (preferably a BOOTABLE CLONED backup created with either CarbonCopyCloner or SuperDuper), or have kept an archived version of the 10.14.4 installer (or the 10.14, 10.14.1, 10.14.2 or 10.14.3 installer with an additional copy of the 10.14.4 updater), you're probably NOT going to be able to "get back" to 10.14.4 without some fancy twists-and-turns.
Can Mainstage be upgraded?
IMPORTANT:
I have sent you a private msg. which is viewable at your "conversations" page here.
READ IT.