Mac needs to repair library after changing location of home directory

NOTE: I got this same error after upgrading from El Capitan (10.11) to Sierra (10.12), so hopefully this will work for your issue.

Steps I took to resolve this:

1. Open Terminal and copy the following: "defaults write com.apple.Finder AppleShowAllFiles YES" (do not sudo) and hit return. Then type "killall Finder" and hit return.
2. Using Finder, select Go > Computer > Macintosh HD > Users > User Folder > User Library. Right click and select Get Info > Permissions
3. In info Library window, unlock to make changes and ensure there are no other users except User and Everyone. Toggle “Read & Write” to “Read” and back to “Read & Write”. Select the gear icon to apply to enclosed items.
4. Close all credential prompt dialogs by hitting Cancel until the prompts stop. Reboot your system and the issue should be resolved.