I do not understand why I have to upload the file again...
It is very likely when you uploaded the file originally, you took the default file security which is Private instead of changing it to Everyone. When the file is uploaded with Private security permission, it is only available for 48 hours.
For more information, take a look at this...https://help.anaplan.com/ebc01b56-7b57-4e36-93de-acfdb75a8441-Overview-of-Private-and-Default-Files
I am trying to re upload the file into DAT03 Historic Volumes but the upload is not taking place