Compute page barfs errors when polling the server for calculation complete

[ericsoco]

The compute page (e.g. http://ubuntu.local:8000/reblock/compute/ericsoco_newproject_newlocation_13/) polls the server for job completion. As it does so, the console spits out 500s: GET http://ubuntu.local:8000/reblock/reload_step/?pr_id=13 500 (INTERNAL SERVER ERROR)

Once the job completes, the 500s change to client-side errors:
Uncaught TypeError: Cannot read property 'replace' of undefined
I assume this is the client trying to swap in the completed map.

[ericsoco]

The computed map will eventually appear (even without refresh), despite all the errors.