Modules & VBA :: Import From Excel (variable Ranges)

I am trying to import data from an Excel file to MS Access (2013).

The Excel sheet consists of 700 columns. A group of 7 columns (always same header) are to be implement in Access one among the other.

That means:

At first columns A-G, than columns H-N, than columns O-U

I am trying to solve this with a loop (as you can see in the code)

But, if I start the modul I get this error:

"Runtime error 1004. The method Worksheets for _Global object failed"

But the module works, of I start it a second time. The error message appears only at the first start.

Apart from that, the code works. Sometimes, the module imported empty rows into the Access table.

Code:
Sub ExcelImport()
Dim xlApp As Excel.Application
Set xlApp = New Excel.Application
xlApp.Workbooks.Open FileName:="C:Users...DesktopBeispiel.xlsx"

[Code] ......