When I launch it manually, it shows this in console:
2015-05-14 3:12:17.931 PM Finder[260]: TotalFinderInjector: You have Finder version 10.10.4. But TotalFinder was properly tested only with Finder versions in range 10.8.0 - 10.10.1.
Is there an update coming?
Please install this version: http://totalfinder.binaryage.com/beta-changes#1.6.18
It is still on beta channel. I will publish it to everyone soon(ish).
FYI new 1.6.19 should explicitly address this issue: http://totalfinder.binaryage.com/beta-changes#latest