After upgrading (from an almost 1 year old version), I receive an error

[Core Exception/PhutilMissingSymbolException] Failed to load class or interface 'PhutilKeyValueCacheAPC': the class or interface 'PhutilKeyValueCacheAPC' is not defined in the library map for any loaded phutil library. If this symbol was recently added or moved, your library map may be out of date. You can rebuild the map by running 'arc liberate'. For more information, see: http://www.phabricator.com/docs/phabricator/article/libphutil_Libraries_User_Guide.html

Am I supposed to have to run arc liberate when I didn’t develop my own module?
The upgrade guide does not state this would be necessary.

I ran arc liberate from the arcanist and phabricator folders successfully, which resulted in changes in phabricator/src/__phutil_library_map__.php (which shouldn't be there?). I also tried running arc liberate from libphutil, which errored and stated there were multiple modules.
Liberate did not help.

(I’d have loved some version numbers on this upgrade, to know where I might expect breakage.)