This might help --
Adobe has changed what happens when you update to a new version of CC software. When you installed CC 2015, it removed your previous version of the software and deleted your fonts, assuming you will only be using fonts from TypeKit.
You'll need to reinstall CC 2014 to get your fonts back or use TypeKit. Open the CC app and find the previous versions, find the version you want, and install it.
I got this info from InDesign Secrets:
By default, if you install CC 2015 apps, your previous versions will be removed. This is a huge change from the way it used to work.
Adobe believes (although many of us disagree) that most Creative Cloud users only want the current version of their Creative Cloud apps. So beginning with this release, it has changed the default so previous versions will be uninstalled by default, and settings will be migrated to the new version. If you're happy with that, then in the Update dialog box, just click Update.
If you want to change that, here's how: after you click Update, click Advanced Options. Then in the Advanced Options, deselect "Remove old versions," then click Update.
Thank you for your reply fiddles5. Where do I download CC2014 from? I cannot see it on the Adobe site.
Still having problems, but only with some fonts.
If you, or anyone else can help me that will be great. Feel like throwing my machine out of the window at the mo.
The upgrade to CC2015 might remove the older versions if you chose that option, but it wouldn't delete fonts in your system's font folders.
Is Franklin Gothic showing up in other applications? Have you tried user/Library/Fonts, or /Applications/Adobe InDesign CC 2015/Fonts (where they would only be available to ID)
Thanks for your suggestions Peter Spier and Rob Day, sadly my font problem has not been fixed, however. If anyone else has an top tips please email me.