Recently I was assigned an issues at one of our client which was related to SharePoint 2013 and Reporting services integration mode. The client was running Reporting services in SharePoint 2013 integration mode.
After publishing report to SharePoint when you open the context menu for any report and click Manage data sources it was throwing an error which read:
We tried redeploying the reports but that did not help. On further research we found that for whatever reason it was adding an extra semi-colon in the URL
Notice the semi-colon just before the ID parameter. If you remote the semi-colon the page will work just fine but that was not the solution that I was looking for.
After some research it was found that the Reporting Services was not configured properly and hence the error.
The solution in this case was to re-install Reporting Services component.