Issue Summary

Going to space settings > Look and feel, in the option template, if you click to edit a blueprint template, instead of opening the screen to edit the content's, it display a message "We’ll be back in a flash
We’ve encountered a small problem, but we should have it sorted out soon."
Same message appear when trying to edit it on the global templates. 
Custom created templates does not trigger the error.

Steps to Reproduce

1. Create a space
2. Go to Space Settings > Look and Feel
3. Click on Templates
4. Look for Blueprint template e.g: HR Knowledge Base Management
5. Click to edit this blueprint
6. Go to Confluence Settings > Global templates
7. Try to edit a Global Blueprint template

Expected Results

You are redirected to the edit template page

Actual Results

Message displayed: 

"We’ll be back in a flash
We’ve encountered a small problem, but we should have it sorted out soon."

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available