Octolapse installs, but does not show up

What is the problem?
Tried installing Octolapse from plugin manager. Said it was successful, and reboot as usual- however it did show us as Install: unknown
What did you already try to solve it?
Reboot system, re-install...no difference
downgrade pip to 10.0.1...no difference
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, octoprint.log, serial.log or output on terminal tab, ...)
Octoprint 1.3.9
Octopi 0.15.1
octoprint.log (259.3 KB)
plugin_octolapse.log (165 Bytes)

update: Went back to 1.3.8 and everything works fine