Error upgrading from 1.9.1 to 2.0.14

I am having trouble upgrading from CB 1.9.1 to 2.0.14. (I am on Joomla 2.5.28 and intend to migrate to 3.6. I have previously migrated from 1.5 to 1.6).

When I try to use the Extension Manger to install the Community Builder package I get the following errors in the log file:

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!

My error reporting is set to 'simple' and debug is on. (If I set error reporting to maximum I get lots of errors for improperly calling static functions).

I am running under IIS 10. All directories in system information show as writable but configuration.php shows as unwriteable, which makes little sense since the Properties dialog shows that all users including IIS_IUSRS have full control. PS: the configuration.php shows as writable before the install attempt and unwritable after the install has failed.

I have PHP 5.4.45 installed and MySql 5.7.10.

Any suggestions as to what I might try. (I am working with a clone of the site and can easily restore.)

Package Installer is not tested in a migration setting. Unzip it and within extensions/packages/ install the zip file there directly as that's the CB package it self to see if any errors become more clear. You're not doing an upgrade, but are doing a migration. This means settings could be lost, etc.. I recommend unpublishing anything that integrates with CB (Kunena, K2, even CBSubs system plugin, etc..) to avoid CB 1.x API loading during install and causing odd conflicts.