The list separator is the character that separates parameters.
The default setting in Excel is dependant on your windows regional settings. In America the list separator is a , and in Sweden (and most of the world) it's a ;
If there is a mismatch between the Settings in the report and in Excel you will get the following error message:
To solve this you do the following in Exopen Report: Make sure you are logged out and click Admin -> Settings
Change the List Separator / List Separator Sheet to either , or ; until and try using the report until you find a combination of the two that works.