VBA macro crashing Excel 2010 - vba

Question

I have an Excel 2010 spreadsheet that I use to maintain tests for an automated test application written with Selenium WebDriver. The spreadsheet has 6 ActiveX buttons that Upload (to a database), Import (from another sheet), Clear All Sheets, Export (to another sheet), Merge (two sheets), and Restore (a test suite from the database). My problem seem to stem from the macro that runs when the Import button is selected
The macro takes two sheets, source and destination, clears the destination sheet and copies the cells and data from the source workbook to the corresponding sheet in the destination workbook. From there, it can either be uploaded to the database or run from the sheet by the testing app
A couple weeks ago when selecting the Import button Excel crashed. I looked on the web and found a solution that worked. It involved disabling all macros, shutting down trust documents and trusted locations, recompiling, and reopening the workbook. This worked for a couple weeks until the same thing happened again this past weekend and the fix did not work anymore.
Here is the code I have:
numSheets = wrkBook.Sheets.Count
appName = wrkSheet.Cells(2, 3).Value
bkPath = Application.GetOpenFilename("Excel Macro-Enabled Workbook (*.xlsm),*.xlsm")
If bkPath <> "False" Then
Call Clear_All(wrkBook, wrkSheet)
'get the number of sheets in the source workbook
destCnt = wrkBook.Sheets.Count
Set importBook = Workbooks.Open(bkPath)
For a = 1 To destCnt
thsShtName = wrkBook.Worksheets(a).Name
'activate the source workbook
importBook.Activate
'get the numer of sheets in the source workbook
srcCnt = importBook.Sheets.Count
'loop through each sheet checking title
For b = 1 To srcCnt
'get the name of the 'a' sheet
**srcSheetName = importBook.Worksheets(b).Name**
'do more stuff with the source sheet
Next b
Next a
End If
The code is crashing on the following line
srcSheetName = importBook.Worksheets(b).Name
Here are a few things that I have noticed. Once the importBook variable is set, I cannot expand the variable in a watch window even if the code has not reached the offending line. However, the macro will successfully get the srcCount (number of sheet on the source sheet). Once the macro gets to the offending line it crashes consistently with a message stating simply that Excel has encountered an error and needs to close . No information, Excel closes, and sometimes restarts to a blank workbook

Answer 1

OK...I figured this out myself after heeding Siddarth Rout's suggestion about a corrupt spreadsheet. I took the steps that I described above
So here's what I did.
I copied one of the other spreadsheets and cleared it. As soon as I ran the Import macro, it passed through the line where it was failing before, so a corruption seems to have been the issue. I then stepped through the original code and rewrote the Import macro to simplify the code in it. It now seems to be working just fine
Thanks for the suggestions!!