I Exported Data of Asset Type -> Workstation CSV. 

Made one single change in a column ( Just to test, I did Not create any column or changed anything from the original-file)

Then tried to upload back into SDP

Got this error on 95% records. 

Failed

[ResourceLease] Column 'STARTTIME' cannot be null

Resulting the failure of update. there's no such column called STARTTIME. it must be referring to something else.