Yes, it would appear the URL limitations of SharePoint Integration are the cause of the above error.

I was hoping to jump around it since I can use the paths to navigate to the reports.

Does anyone have a step-by-step instructional on how to move SSRS 2008 R2 reports from SharePoint Integrated mode to SSRS 2008 R2 native mode that will also bring over the subscriptions? I have quite a few reports, each with 30+ subscriptions, and each subscription is unique.