Error after Windows 10 reinstallation

[Binome]

Hi,
I have reinstalled my Windows 10 computer and have an error for 2 different synchronization tasks depending on the same partition (2 tasks because of 2 backup locations). The error tells:

Impossible de verrouiller les répertoires des dossiers suivants :

Impossible d'écrire le fichier "E:\sync.ffs_lock".
ERROR_PRIVILEGE_NOT_HELD: Le client ne dispose pas d’un privilège nécessaire. [CreateFile]


It's french and simply tells it can't write the sync.ffs_lock because of privilege.
What should I do?
Thanks.

[Plerry]

It seems the user under which credentials FreeFileSync (FFS) is run does not have Write privileges (and possibly not even Read privileges) in E:\

[Binome]

I have granted total privileges for all users thinking that was the problem but no change.
What could I do?

[xCSxXenon]

What is "E:\"?