Please follow the bellow steps for recover Subdis file:---

Note :- First Copy Marg folder for safety Purpose...

Go to  Marg folder>  Open Data folder > Search "SUBDIS" > Check extension > Delete/Rename corrupted extension financial year file > Start Software > On Marg gateway Press "ESC" key > Save to quit--- "YES" > Window will ask option of backup > Select Financial year/Company > Press enter Software will ask about  recovery and path of backup exist > Select backup file from which you want to recover > Start software.

>>After the follow above steps need to run File maintenance.