F945 do not display distance, speed and pace are displayed . Acivities not savable . Hard reset , activities discarded on garmin folder : No change ! still no distance . any suggestion ?

Sounds like you open the activity but do not push the start button. 

Mine started doing the same thing today...both swim and run had zero diatance and didn't show as saved

Exactly same here. Definitely started right after 7.10 update.

Tried soft and hard reset, reinstalling maps. Also had trouble to reconnect it to my phone and computer. After some time playing around with it, it now works again. I am not sure what exactly fixed it, but if you haven't yet, try garmin Express on a PC...

Same issue, but only on the Run activity. Timer, pace, power all looking fine, but the distance stays stuck on 0.0. At first I thought the GPS got borked in the upgrade, but if I do a bike activity, distance works perfectly. 

Anyone have a suggestion for a fix?