When suffering difficulties with OneDrive - In order to re-install/ re-activate OneDrive click on the link below:

Download the OneDrive App for PC, Mac, Android, or iOS – Microsoft OneDrive 

From this screen choose Download. 
Once it has downloaded (top right you will see this) choose to run the file OneDriveSetup.exe and you will see a dialogue box appear just click next and ok til the end and you will see a blue cloud appear bottom right of your screen. OneDrive is now activated.