If your package didn’t deploy, my guess is that 7.7.6 is still the version before the upgrade attempt. you can check that on the top-right menu, “About” option.
7.7.6 is from around September 2016, was that when you first installed it?
When you try upgrading, which version did you download from SuiteCRM site?
You can check upgradeWizard.log to get more info, and valuable error messages.