Installation error "Failed to uninstall self. Please uninstall manually"

On my J2.5.28 site, I've attempted to upgrade CB 1.9 to the latest version (2.0.14+build.2016.06.29.00.16.20.56df57006(latest)) and received a "package component success" message, along with "Failed to uninstall self. Please uninstall manually."

I then manually uninstalled CB 1.9 and tried again, receiving the same error. I then purged the expired files cache and tried a third time, resulting in the same error message.

Here is the log:

001_pkg_communitybuilder_2.0.14+build.2016.06.29.00.16.20.56df57006.zip is being installed.
001_pkg_communitybuilder_2.0.14+build.2016.06.29.00.16.20.56df57006.zip failed to install!
001_pkg_communitybuilder_2.0.14+build.2016.07.19.01.59.29.f1d8bdbed.zip is being installed.
001_pkg_communitybuilder_2.0.14+build.2016.07.19.01.59.29.f1d8bdbed.zip failed to install!
Installer is uninstalling.
Installer failed to uninstall!

That message means the package installer failed to uninstall it self. The log specifically states this as "Installer is uninstalling." followed by "Installer failed to uninstall!". It means you need to manually uninstall Package Installer within Extensions > Management.

However, CB 2.x didn't install to begin with. Please understand you are not doing an upgrade, but a migration. This should be done on a clone of your site so you know what to expect. Please revert to a backup before the install which you hopefully made. Otherwise attempt to install CB 2.x over it self to see if that resolves it.

If you've a backup then clone your site and on the clone enable debug mode and maximum error reporting. Once done install and see if any errors occur. Please verify you also meet the minimum requirements below.

www.joomlapolis.com/documentation/276-community-builder/getting-started/18576-technical-requirements-for-community-builder

If you migrated to Joomla 2.5 or Joomla 3.x please also review the below carefully.

www.joomlapolis.com/faq/18478-migrating-from-joomla-25-to-joomla-33