On the PC go to device manager Plug the cable connected to the remote control or the mavic to see wich driver the system is using. Remove the driver. Probably you'll see an exclamation mark on it.
unplug an Plug again one of the devices and see if the driver appears without errors.
If nothing appears, check to see hardware changes on top of device manager.
See if the drivers appears without errors
I also strongly sugest, if you can, to do the update on another pc,
Sometimes there are some issues around the updates. Dont give up there's always a solution.
If you can't solve the problem talk to DJI.
In case of an anomalie they'll fix it
Thanks a lot for your help and espacially with DJI assistant software !
How to use DJI Assistant software :
In fact I succeeded to update the firmware for the remote by connecting it directly to the computer yesterday night, then i tried to update with the DJI GO application that failed and the with the Mavic directly connected to the computer but it failed, as i connected it the software told me that i had "firmware incompatibiliy detected between some modules and current device"...
I tried to update a few times like this directly for the .0500 version of the update and it always failed...
This morning i had the same issue about the message but i did try to update first for the .0400 version of the update... and it succeed !
Then i stopped the mavic and tried to update again with the DJI assistant software, no more message about firmware incompatibility !
i did the update to the .0500 version and succeed !
Thanks again for the Help Pierce ! hope that it coud help someone else...Fly safe !