Shrug ie 404 template seems broken

[jaywink]

Template render error: (/app/views/shrug.html) [Line 5, Column 12]
  attempted to output null or undefined value
    at Object._prettifyError (/app/node_modules/nunjucks/src/lib.js:36:11)
    at /app/node_modules/nunjucks/src/environment.js:563:19
    at Template.root [as rootRenderFunc] (eval at _compile (/app/node_modules/nunjucks/src/environment.js:633:18), <anonymous>:19:3)
    at Template.render (/app/node_modules/nunjucks/src/environment.js:552:10)
    at /app/node_modules/nunjucks/src/environment.js:366:27
    at createTemplate (/app/node_modules/nunjucks/src/environment.js:315:9)
    at handle (/app/node_modules/nunjucks/src/environment.js:327:11)
    at /app/node_modules/nunjucks/src/environment.js:339:9
    at next (/app/node_modules/nunjucks/src/lib.js:328:7)
    at Object.asyncIter (/app/node_modules/nunjucks/src/lib.js:334:3)

Also should probably have a generic "oops things failed" handler to avoid stacktraces to users.