Andrew, you aren’t alone. We were surprised to find that, contrary to assurances from Adobe, that plugins for InDesign CC 2014 may not be fully compatible with InDesign CC 2014.1. In all likelihood you are in a similar situation where a _third-party plug-in_ is causing the crash.
As a third-party developer, we’re in a unique situation where we can either recompile using the 2014.1 SDK (which shouldn’t be required but fixes the crash) but lose compatibility with 2014 (10.0) users, or we use the original 2014 SDK (which should be compatible with 2014.1, but apparently isn’t) but crash InDesign CC 2014.1. Obviously we’re choosing the former of recompiling our plug-ins using the 2014.1 SDK and encouraging customers to update to the October release (if they haven’t already). We’re also working with Adobe to identify what changed in the release build (x71) as our plug-ins were working fine during pre-release testing (up to build x70).
As far as re-installing the June release, it’s definitely possible but you cannot have both the June (10.0) and October (10.1) releases simultaneously installed. Do the following:
# Launch the Adobe Creative Cloud desktop application.
# Go to the Apps tab
# Scroll down past your _Installed Apps_ to the _Find New Apps_ section.
# To the right of the section heading, you’ll see a text ‘button’ labelled _Filters & Versions_; click that and then choose _Previous Version_
# Now when you click on the InDesign _Install_ button you should see options for CS6 8.0, CC 9.0, and CC (2014) 10.0.