Hello,
I am working on a workbook which contains INDEX/MATCH formula in which the source is coming from a different file.
It was working perfectly for a couple of days and eventually it stopped. I checked the formulas and noticed that the
formula on the INDEX/MATCH automatically changed. See the difference between the two below:

Original Formula:
=IF(ISNA(INDEX('\\DCSERVER01\[BERSACCOUNT1.xlsx]Sheet1'!$A:$A,MATCH(B4,'\\DCSERVER01\[BERSACCOUNT1.xlsx]Sheet1'!$C:$C,0))),"",INDEX('\\DCSERVER01\[BERSACCOUNT1.xlsx]Sheet1'!$A:$A,MATCH(B4,'\\DCSERVER01\[BERSACCOUNT1.xlsx]Sheet1'!$C:$C,0)))

The New Formula:
=IF(ISNA(INDEX('C:\[BERSACCOUNT1.xlsx]Sheet1'!$A:$A,MATCH(B4,'C:\[BERSACCOUNT1.xlsx]Sheet1'!$C:$C,0))),"",INDEX('C:\[BERSACCOUNT1.xlsx]Sheet1'!$A:$A,MATCH(B4,'\C:\[BERSACCOUNT1.xlsx]Sheet1'!$C:$C,0)))

Things to consider:
1. No one can modify the file since I am the only one who has access of this file on the network.
2. The cells where these formulas are encoded are all locked
3. The workbook is locked and you cannot click on the locked cells
4. The workbook is password protected


Thank you so much.