Created attachment 986757 [details]
Attempt at installing Thunderbird-regardless of GUI chosen

+++ This bug was initially created as a clone of Bug #928851 +++
Perhaps also related to: Bug 1116499, Bug 928851, or Bug 1121656?

Description of problem:
  No GUI software installation is possible.  Both gnome-package and apper
  fail with IDENTICAL error message: "A problem that we were not expecting
  has occurred. Please report this bug with the error description."

How reproducible:
  100%, everytime.  Problem exists with Fresh Install Fedora21 using server,
  selecting Desktop Developer package and other packages...

Steps to Reproduce:
  1) With fresh server install of F21 Desktop Developer
  2) Attempt to install any package with default gnome packagekit
  3) Receive error message

Expected Results:
  Should install packages.

Actual Results:

  COMMAND LINE INSTALLS WORK - such as 'sudo yum install apper'

  No GUI software installation is possible.  Both gnome-package and apper
  fail with IDENTICAL error message: "A problem that we were not expecting has
  occurred. Please report this bug with the error description."

  Details shows: "SearchGroups not supported by backend"

I am able to search for and find packages I wish to install (if not using group names), such as Thunderbird...

"cannot download t/thunderbird-31.4.0-1.fc21.x86_64.rpm to /var/cache/PackageKit/metadata/updates/packages/: Cannot download t/thunderbird-31.4.0-1.fc21.x86_64.rpm: All mirrors were tried"

I am seeing similar words in other bugs "all mirrors were tried" and "A problem that we were not expecting has occurred."