Loading entities from NoScript .dtd files is blocked

Starting with NoScript 5.1.0 there is the following error in the browser console visible:

XML Parsing Error: undefined entity
Location: jar:file:///home/thomas/Arbeit/Tor/tor-browser-bundle/tor-browser_en-US/Browser/TorBrowser/Data/Browser/profile.default/extensions/%7B73a6fe31-595d-460b-a920-fcc0f8843232%7D.xpi!/chrome/content/noscript/noscriptOverlayFx57.xul?1brcl6s241gsnehuud9g
Line Number 27, Column 5:  noscriptOverlayFx57.xul:27:5

NoScript is retrieving its XUL overlay template through XMLHttpRequest which seems to break due to failing entity resolution.