#1100 Error thrown in console on reply with enigmail in epyrus

[Moonchild]

When replying to a reply in Epyrus with Enigmail installed, the following error is thrown (2x):

Error: ReferenceError: Ci is not defined
Source File: chrome://enigmail/content/ui/enigmailMsgComposeOverlay.js
Line: 4511

Doesn't seem to affect actual usage of the extension but seems to at least miss out on intended re: consolidation in the subject.

Version in use 3.1.4

  fixMessageSubject: function() {
    let subjElem = document.getElementById("msgSubject");
    if (subjElem) {

      let msgHdr = Enigmail.msg.getMsgHdr();
      if (msgHdr) {
        if (msgHdr.flags & Ci.nsMsgMessageFlags.HasRe) {   <*** error ***
          subjElem.value = "Re: " + subjElem.value;
        }

        let r = subjElem.value.replace(/^(Re: )+/, "Re: ");
        if (r !== subjElem.value) {
          subjElem.value = r;
          if (typeof subjElem.oninput === "function") subjElem.oninput();
        }
      }
    }

[Patrick Brunschwig]

That's weird - I can't confirm this. Ci is globally available.Do you have any other addons installed that might have modified Ci?

[Patrick Brunschwig]

Nevertheless, I replaced it with Components.interfaces.

[Moonchild]

Do you have any other addons installed that might have modified Ci?

Not that I'm aware of, but I'm not running the default theme so maybe the default theme globally defines Ci and this one (ClassicTB2 for Epyrus) does not?

Attached my list of extensions in case it gives any insight.