"...,right-click and choose Smart Sync & then local."
The combined subject line, made this one hell of a problem today.
Hopefully this was not me being an idot...
Recently purchesed security product.
Firewall prevented "only online" files from opening.
I keep everthing cloud side, no local.
Reset the fire, and boom shakalaka, success.
Took me hours, hopefully it takes you about as long as reading this.
Peace & blessings