Excel not working after working with Autoit

[Rskm]

Hi, I am using excel as input media for my program. The excel file (i tried with .xls, .xlsx and .xlsm format) has inputs which the autoit script reads during the run and performs few calculations. Some times (not always), after the run, when i try to open the excel file manually, the file doesnt open at all in excel. see the screenshot attached. However, if the execute the autoit script, the scripts still reads the existing data from that excel and performs the calcs. I copied the excel file to another computer and there too, it doesnt open.  So, after this, i cannot edit the excel forever (if i need to change any inputs). It is only this particular file that got affected. other excel files works normal.  What could be the problem here.  please help as this is a new challenge for me during my program development. 

Edited December 29, 2019 by Rskm
added the last line

[Danp2]

Hard to say without seeing your script. Chances are that you aren't closing the file in your script or there's a hidden copy of Excel holding a lock on the file.

[water]

The most common cause: You have opened a Workbook hidden, saved it but forgot to reset the hidden attribute beforehand.

How to manually unhide the workbook is described here.

Edited December 29, 2019 by water