Copying a link and using "Paste & Go" results in error

As noted in our blog (https://blog.torproject.org/comment/284045#comment-284045): if one copies a link (pure text does not trigger the bug) and opens it in a new tab with by right-clicking on the URL bar and choosing "Paste & Go" an error is showing up in the browser console:

Received unexpected result type undefined, falling back to typed transition. WebNavigation.jsm:217
onURLBarUserStartNavigation re[/gre/modules/WebNavigation.jsm:217](/gre/modules/WebNavigation.jsm:217)
observe re[/gre/modules/WebNavigation.jsm:136](/gre/modules/WebNavigation.jsm:136)
_notifyStartNavigation re[//modules/UrlbarInput.jsm:1364](//modules/UrlbarInput.jsm:1364)
_loadURL re[//modules/UrlbarInput.jsm:1240](//modules/UrlbarInput.jsm:1240)
handleCommand re[//modules/UrlbarInput.jsm:446](//modules/UrlbarInput.jsm:446)
_initPasteAndGo re[//modules/UrlbarInput.jsm:1333](//modules/UrlbarInput.jsm:1333)

That issue is not showing up in Firefox 68 it seems. Thus, this is a bug on our side.