I have downloaded the annotations that I have made with the new session after I realized that all my previous annotations have been lost. What happened is that I kept my Lumin session open, as an open tab of Chrome, just re-authenticating when my auth token expired. During all that time, since end of July I did not get any GDrive sync error message. I had to reboot my computer recently. And when I reopen Lumin today, I was surprised not to see any of the annotations. And I checked in GDrive, where I noticed the last modification of the native PDF was July 26th !! So I reopen Lumin, and then I noticed the tiny GDrive icon with an orange mark.... and after you know what happen... I click, the sync error message, the advice to download the modifications, ect... but all my previous annotations from July 26th were already gone...

1- investigate the reason of this 'memory bound error' that blocks the sync. It sounds like a tiny memory leak that surfaces when users keep their session open too long.

2- be sure that the sync warning is more visible in the UI. If I had seen it, I would have downloaded the annotations as suggested