Resolve 14 to 15

Will I lose any projects if I update to the free Resolve 15 from the free 14?

When I upgraded I didn't lose any -- but good practice is to backup your projects first -- just in case, then you can always roll-back if necessary.

Patrick Inhofer has a good list of what to do when upgrading from Resolve 14 to Resolve 15 on MixingLight:

Guide: How Do You Safely Upgrade to DaVinci Resolve 15?
https://mixinglight.com/color-tutorial/ ... esolve-15/

I think this is good advice for any major software upgrade: backup all your data files; backup all your source files; backup your boot drive (so you can revert if necessary); backup your current projects. THEN do the update.

In the case of Resolve, I think it's also important to backup the Project Database, on the rare possibility that a session loses something in translation. In general, it does work pretty well, but I had one R14 session where a single timeline had a bunch of flakiness with Camera Settings when it was converted to R15. All the other timelines were fine.