Gateway can't load data from MDB: Error -2147467259 DataFormat.Error

[Sokon]

We constantly get an error when trying to refresh a certain report using the gateway. The report contains an Access 2000 MDB-file as a data source. It's our first report with that sort of source so the error might be a problem in our configuration. 

Here is the error:

Cannot connect to the mashup data source. See error details for more information.
Please try again later or contact support. If you contact support, please provide these details.

Underlying error code-2147467259 Table: t_Zählungen.

Underlying error messageUnspecified error

DM_ErrorDetailNameCode_UnderlyingHResult-2147467259

Microsoft.Data.Mashup.ValueError.ReasonDataFormat.Error

Cluster URIWABI-NORTH-EUROPE-redirect.analysis.windows.net

Activity ID xxxx

Request ID xxxx

Time2018-06-12 12:00:35Z

More information:

• The report refreshes smoothly in the PBI Desktop.
• Microsoft Access Database Engine 2010 (64bit DE) is installed on both the gateway machine and the workstation
• We are located in Germany, so date and number formats are different from those in the US. We already checked all date fields and changed their date format with the "using locale" conversion (it seemed to help in many places, the error message changed the table name where the error occurred)
• The table mentioned in the error doesn't contain any number or date formats - we are out of luck.

Any help is greatly appreciated!

[Sokon · Accepted solution]

Answer to myself: Found a solution, look here.

[Anonymous]

@Sokon,

Please create a small report which connects to the access database without changing locale, and check if you are able to refresh the small report in Power BI Service.

Regards,
Lydia