I’m having a problem similar to maximusx. I’ve been using Mosaico with no issues for about a year. Now, within the last month or so, I regularly lose my saved layouts — they just disappear. No errors, no system crashes — they’re just gone. I’ve removed Mosaico and reinstalled from scratch, and tried some of the other suggestions in that thread. I’m about ready to give up. Sure, I could keep a backup of the layouts somewhere, but now I’m doing someone else’s work.
Currently running v126.96.36.199 under Windows 10, v10.0.16299.