Files sellection box is not active in WD SmartWare

I was using WD backup since years and I never faced any issue. However, recently I deleted my backup from the HDD and when I tried to start the backup again using the file backup option, I couldn’t select the checkbox for any folders/files. These folders/files are in my D drive. However, I can select any files/folders in C drive and the backup is accomplished successfully. FYI, I have WD My passport ultra metal edition and using WD SmartWare Pro V2.4.16

Have you read all the information under the Help tab?

Yes I read most of the backup information under the help. But the same.

Any update on this? is there is any possible solution?