How many nodes can you install SSRS on when using basic availability groups? I have migrated a SQL Enterprise standalone SSRS installation to a new SQL Standard 2 node Basic AG recently.  I got the expected "scale-out-deployment is not supported error", and I resolved that by removing the old server's information from the keys table in the reportserver DB. I now have just 2 lines in that table, a NULL machine name and Node1.  the report server works perfectly fine on Node1 right now, but when i fail over to node2 I get the "scale out feature is not supported" error when I go to the web service URL link(http://Node2:80/Reportserver), but NOT when i go to the web Portal URL link (http://node2:80/Reports).  That gives me access to the reports fodlers, but when I try to launch a report I get the Scale out error.

If I restore the encryption key, it works fine, despite having already restored the encryption key previously.

Can I not have SSRS installed on both nodes of a basic availability group?  Should it be installed on Node1 only?  If so, will I still be able to access the shared reportserverDB?

This is my first attempt with basic availability groups, I didn't run into this issue at all with my last enterprise install since I was using scale-out deployment.

Just had another thought...  the source DB that the reportserver is pulling data from is in a different AG since basic AG's can only have 1 DB in them.  if that DB is on a different node then what reportserver and reportservertempDB are running on, could that be a problem?  would the source DB need to be failed over as well?
A SSRS scale-out deployment is an Enterprise Edition ONLY feature.  

I don't like providing link-only answers, but this alternative approach outlined by Rodney Landrum, is much too long to copy/paste into an answer, and I suspect his blog entry will be around for quite some time as it's hosted by Red-Gate.

Long story short, you can't approach this via a scale-out deployment, but there is an alternative solution available if you don't mind some additional administration and automation required to make it happen.