Extension errors after a while of surfing with Tor Browser based on ESR68

I see extension errors in my console after a while of surfing:

Extension error: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIDOMWindowUtils.removeSheetUsingURIString]"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: re[/gre/modules/ExtensionCommon.jsm](/gre/modules/ExtensionCommon.jsm) :: runSafeSyncWithoutClone :: line 75"  data: no] undefined 75
[[Exception stack
runSafeSyncWithoutClone@re[/gre/modules/ExtensionCommon.jsm:75:12](/gre/modules/ExtensionCommon.jsm:75:12)
cleanup@re[/gre/modules/ExtensionContent.jsm:403:11](/gre/modules/ExtensionContent.jsm:403:11)
close@re[/gre/modules/ExtensionContent.jsm:913:14](/gre/modules/ExtensionContent.jsm:913:14)
inner-window-destroyed@re[/gre/modules/ExtensionContent.jsm:998:19](/gre/modules/ExtensionContent.jsm:998:19)
observe@re[/gre/modules/ExtensionContent.jsm:1016:27](/gre/modules/ExtensionContent.jsm:1016:27)
Current stack
runSafeSyncWithoutClone@re[/gre/modules/ExtensionCommon.jsm:81:9](/gre/modules/ExtensionCommon.jsm:81:9)
cleanup@re[/gre/modules/ExtensionContent.jsm:403:11](/gre/modules/ExtensionContent.jsm:403:11)
close@re[/gre/modules/ExtensionContent.jsm:913:14](/gre/modules/ExtensionContent.jsm:913:14)
inner-window-destroyed@re[/gre/modules/ExtensionContent.jsm:998:19](/gre/modules/ExtensionContent.jsm:998:19)
observe@re[/gre/modules/ExtensionContent.jsm:1016:27](/gre/modules/ExtensionContent.jsm:1016:27)
]]

Not sure what is trigger those.