Indirect Function returns a #REF error

Question

My INDIRECT function (EXCEL 2010) suddenly stopped working after it was working before.

I have workbook A and workbook B.  Different worksheets in Work B have different cells with  formula INDIREC to reference the  worksheets in workbook A.  I opened workbook A, then workbook B, I could see the values extracted by the formula INDIRECT.  However, I immediately got the following Excel warning: an Excel warning "This workbook contains links to one oor more external sources that could be unsafe..... "  After I click on the update box, all the values changed to #REF.  The upper left hand corner of each cell shows a green triangle mark.     Also, how do I interpret the Edit Links display?  For example, the Location: shows a complete different workbook name.  None of the files in the links has anything to do with the source file?

I have the same setup for several other workbooks and they all have the same problems which I never had before.  Help!!!

[Moved from: Office / Excel / Microsoft Office Programming / Office 2010]

Answer 1

It is possible that either of the following has got changed

(a) the cell reference

(b) the worksheet name

(c) the workbook name

(d) the file path / the folder where the file was originally stored

The reason for this is that invariably, one has to hardcode some part of the INDIRECT formula.