error running a paginated report with subreports in the on-premise reportViewer.aspx control

[Gourd_J]

Power BI Report server version: Version 1.3.6816.37243 (August 2018)

I have a paginated SSRS report that reads the report server database's catalog in order to list reports available to be run. 

When a user clicks a row the action for the textbox uses this piece of code to show the report in the Catalog.Path in the server's reportViewer:

=Globals!ReportServerUrl + "/ReportServer/Pages/ReportViewer.aspx?%20" + Fields!Path.Value + "&rs:Command=Render"

This works great for all standard paginated reports. But, I just created one with a subreport and it is throwing the following error:

e ERROR: Throwing Microsoft.ReportingServices.ReportProcessing.ReportProcessingException: , Microsoft.ReportingServices.ReportProcessing.ReportProcessingException: An unexpected error occurred in Report Processing. ---> System.UriFormatException: Invalid URI: A Dos path must be rooted, for example, 'c:\'.

I can run the report by directly clicking it on the report server, but when it is run through the reportViewer.aspx control it fails.

Any ideas?

[d_gosbell · Accepted solution]

Why do you have the %20 in front of the path? I would try removing that as it seems like the error is complaining about the path being incorrect and I can't think why you would need this. 

[Gourd_J]

That fixed it!
So weird that it only affected the report with a subreports, I guess it blew up the path of the subreports?