Runtime Error 1004 - Method Rows Object_global Failed

I've got an excel spreadsheet that has a search function on it. There is a hidden tab where all the data sits, and a visible tab with a search button where you can enter a reg of a car and it brings up details from the hidden tab.

This works perfectly when I open the excel file that is on my machine. I've put the excel file on the intranet, and to open it you click a link, and when the pop up box comes up, you click 'OPEN', and the file opens up within IE. When I try and search for a reg, I get the following error!

Run-time error '1004':
Method '' of object '_Global' failed

Its really confusing because this didnt used to happen before.. so I cant see why there would be an error with the code because it used to work!

Here is my code.


Sub Button1_Click()
'Sheet module code.
'Find my data in the indicated range, on this sheet!
Dim strMessage$, strTitle$, strDefault$, strShtNm$
Dim lngMyCol&, lngLabelRow&
Dim varRegID As Variant
Dim rngMyData As Range
Dim cell As Object