Open Published Workbook option from Toad Data point Viewer gives Value cannot be null error

I created a Workbook linked to data on TIC with Toad Datapoint Viewer, I published this workbook on TIC. Now I want to open that workbook from TIC but I get the error message: "Value cannot be null" an another illegible message below it (see attachment). Goin to TIC with a browser does allow me to download and open the workbook. The workbook and the selected datasources do not have parameters or variables.