Template context menu doesn't appear in some cases, for example when clicking the infobox on https://en.wikipedia.org/wiki/The_Fighting_Temeraire?veaction=edit.
Error message in the browser console:
Uncaught TypeError: Cannot read property 'getPrefixedText' of null
at Object.ve.ui.MWDefinedTransclusionContextItem.static.getMatchedTool (<anonymous>:745:772)
at Object.ve.ui.MWDefinedTransclusionContextItem.static.isCompatibleWith (<anonymous>:745:94)
at collect (load.php?lang=en&modules=ext.visualEditor.articleTarget%2Ccore%2CdesktopArticleTarget%2Cmwlink&skin=vector&version=1ctog:655)
at VeUiContextItemFactory.ve.ui.ModeledFactory.getRelatedItems (load.php?lang=en&modules=ext.visualEditor.articleTarget%2Ccore%2CdesktopArticleTarget%2Cmwlink&skin=vector&version=1ctog:655)
at VeUiDesktopContext.ve.ui.LinearContext.getRelatedSourcesFromModels (load.php?lang=en&modules=ext.visualEditor.articleTarget%2Ccore%2CdesktopArticleTarget%2Cmwlink&skin=vector&version=1ctog:650)
at VeUiDesktopContext.ve.ui.LinearContext.getRelatedSources (load.php?lang=en&modules=ext.visualEditor.articleTarget%2Ccore%2CdesktopArticleTarget%2Cmwlink&skin=vector&version=1ctog:649)
at VeUiDesktopContext.ve.ui.DesktopContext.isEmbeddable (<anonymous>:1126:840)
at VeUiDesktopContext.ve.ui.DesktopContext.updateDimensions (<anonymous>:1125:472)
at later (load.php?lang=en&modules=oojs-ui-core%2Coojs-ui-widgets|oojs-ui.styles.icons-interactions&skin=vector&version=u0mdi:3)