Hello Peter.
Two Questions.
1. How did you get the Password Manager? Are you trying to install directly or downloaded from Forge and are trying to publish (seems the later to me)?
2. Do you have Silk UI installed?
If you install directly from Forge (from inside Service Studio, the black tab), it will install any dependences (that is what seems to be missing).
If you try to install it publishing from a downloaded package, you have to guarantee the dependences are present (and it seems you have missing dependences, like Silk UI).
Cheers
EDIT.
Saw now that it does not depend on Silk UI or anything.
So, did you change it anyway?