I am using the KiCad nightly on Ubuntu 16.04.
Today I try to open my project and the schematic are not recognizing the cache libraries, so my schematic is showed with block the not recognized simbols.
I tried to add manually in the “Projec Specific Libraries” as “${KIPRJMOD}/project-cache.lib”.
Someone have so tip to I look to solve this problem?
And the first person affected by the new symbol lib stuff that did not read the plog post pinned to the top. https://kicad.org/post/symbol-lib-table/
Hm. maybe I should repin it on Sunday for a week then? (set it for 2 days)
[edit] just changed the title of that post slightly. Might add a couple of exclamation marks if more people with broken installs turn up 
Sorry, I just saw now. I got I little crazy with the error.
Trying now to return the KiCad version, cause I couldn’t migrate the library yet.
You could try to rename the cache lib and add it as a project specific lib. (If it holds symbols that are not in your library otherwise.)
I find it amazing how many people expect that the nightly build version is “stable”.
I think the guys managing the download pages should add a bit more warning messages about nightly.