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After clicking 'Open' in the dialog 'Open: Background' an error message is returned:
'Cannot load background file ..'
The DWG file is written in a newer format as supported by the used PTV Visum release.
If you want to find out, open the binary DWG file in a text editor. The first characters might be like 'AC1027', which meets 'AutoCAD 2013'.
Recommendation: Update to the current release: