TechTool Pro 10.0.1 is not compatible with Mojave.
There is not going to be a quick fix.
The next release is intended to fix the problems with the Volume Rebuild tool, and to improve the battery test for iOS devices. After that, there will be a release to provide compatibility with Mojave.
The general rule-of-thumb is that you do not upgrade system software until the applications you need to use have had compatible updates.
If you still have a bootable clone, an eDrive, or a Protogo device on which High Sierra is installed, you should boot from that to run the tests.
From
When and How to Upgrade to iOS 12, watchOS 5, tvOS 12, and macOS 10.14 Mojave, by Adam Engst:
Therefore, I recommend that you wait to install Mojave on your main Mac until two things are true:
Apple has released at least 10.14.1, if not 10.14.2. We hope those updates will squash early bugs and smooth out the authorization requests.
You have verified, through community comments or discussions with developers, that your essential apps—particularly utilities!—will run properly in Mojave.
