"The "sheets" method from the "_Global" object have failed."

I have a excel file in a webserver, and the users must run it
directly from the internet explorer.

The problem is : when a user click over the excel table link it opens
the excel in internet explorer but when he/she clicks to run the macro
the macro give some sheet errors.

"The "sheets" method from the "_Global" object have failed."


I dont know why this happen, when the user download and then run
the macro works great, but in internet explorer the macro turns crazy.

Option Explicit

Private Sub Cancel_Click()

Unload Me

End Sub

Private Sub OK_Click()

Dim c As Object
Dim UserName As String
Dim Password As String
Dim MyError As Integer

'Assign UserName to a variable
UserName = UserVerification.UserName.Text

'Assign Password to a variable
Password = UserVerification.Password.Text

'Specify the sheet and range to look up the UserName
With Sheets("Uniformity Check").Range("BQ:BQ")
Set c = .Find(What:=UserName, LookIn:=xlValues, lookat:=xlWhole, MatchCase:=True)
End With

'If UserName cannot be found
If c Is Nothing Then
MsgBox "The username you have enterd is invalid, please try again.", vbCritical, "Incorrect UserName"
Exit Sub
End If

'If Password is correct
If Password = Sheets("Uniformity Check").Range(c.Address).Offset(0, 1).Text Then
ThisWorkbook.Unprotect Password:="mankit_chung"
Sheets("Uniformity Check").Select
ActiveSheet.Unprotect Password:="mankit_chung"
Range("C6").Select
ActiveCell.FormulaR1C1 = UserName
'If the sheet to make visible is not in the workbook an error will occur
'If there is no error then make that sheet visible
On Error Resume Next
Sheets(Range(c.Address).Offset(0, 2).Text).Visible = True
MyError = Err
On Error GoTo 0
ThisWorkbook.Protect Password:="mankit_chung", Structure:=True

'If there was an error let the user know to try again.
If MyError <> 0 Then
MsgBox "The password you have specified is incorrect, please try again.", vbCritical, "Incorrect Password"
Exit Sub
End If
Else

'If the password is incorrect let the user know to try again
MsgBox "The password you have specified is incorrect, please try again.", vbCritical, "Incorrect Password"
Exit Sub
End If

'Dismiss the userform
Unload Me
Call uv_uniformity_check

End Sub

Private Sub UserForm_Click()

End Sub