Recently I ran out of space on a Boot Camp partition with Windows 10 Pro. So I looked around for ways to make more space for Windows by shrinking the macOS partition and enlarging the Windows partition. Apple doesn’t officially support this in Boot Camp without reinstalling Windows, and doing these operations by hand, e.g. with the help of GNU Parted, is time consuming and tedious.
Luckily, I stumbled over Paragon CampTune, a commercial macOS utility (ready for 10.14 Mojave) that automates these tedious tasks and allows to resize the macOS and Boot Camp partitions on the fly, without having to reinstall Windows or macOS.
It finally worked wonderfully, the only irritating thing was that the tool showed a bland error at the first start of the repartitioning process: “Object not found”. After restarting the process with slightly different partition sizes, it could be successfully completed.
I can thus recommend this handy utility as it can save hours of work for a few bucks (ca. 22 USD).