I am using OneDrive to store all my photos, documents, some portable software, PowerShell scripts, and many other things.
I was quite happy with it (especially the Smart File features where I can see and manage all my files on my small tablet) until I realized that my files were not synchronized any more. I then opened Task Manager trying to monitor the OneDrive Sync Engine (named SkyDrive.exe) and saw it kept crashing shortly after being launched.
The first thing you should try is the OneDrive Troubleshooter in the link below:
It is very useful and will try to check for some common problems, automatically fix them if possible and give you the option to reset OneDrive index (this does not remove your files, don’t worry). However, on one of my PC, the troubleshooter kept telling me that my account needed to be an administrator although it was already one. Hence I tried to find a way to reset OneDrive manually, and I found one:
This solved the problem that time and also all the other times OneDrive kept crashing again. The problem sometimes come back after when my computer crashes (i.e. BSOD). I really hope that the OneDrive team can fix this soon (I store more than 60k files on their service), and in the mean time I hope you can use the above workaround to revive your OneDrive should you have the same problem.