User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0

Steps to reproduce:

[TB version 91.0.3]

• open message compose window (new email)
• enter some text in 'Subject' line
• save message (Ctrl + S)

Actual results:

The text/content entered in 'Subject' line becomes greyed out and cannot be edited any longer. Unless message compose window for that particular message is closed and re-opened.

Expected results:

Editing text in 'Subject' line should be possible even after saving message /pressing Ctrl + S - without having to close and re-open the message saved in draft.

Tried Help | Troubleshoot mode?
Probably an incompatible add-on causes the save to error out, causing the re-enabling of the fields (disabled during save) not to re-enable.

Hello Magnus,

thank you very much for your suggestion. Didn't think of that before. Okay, I just tried out Troubleshoot mode but alas the problem still persists.

As for add-ons, I currently only use 'Manually sort folders' add-on.

I also cannot reproduce. But we've had some issues after saving https://mzl.la/3jyOMlY so it's possible to have other bugs.

Can anyone else reproduce?

(In reply to Wayne Mery (:wsmwk) from comment #3)

I also cannot reproduce. But we've had some issues after saving https://mzl.la/3jyOMlY so it's possible to have other bugs.

Can anyone else reproduce?

I can't repro. In fact, the other day I did a CTRL-S and had to modify Subject line of a draft later and was able to bring it up and do so without issue.

I just did the update to TB version 91.1.0 and tried to reproduce the bug. It seems to have been fixed in this version, luckily.
That's why I changed the headline appropriately and added the following: [Fixed in TB 91.1.0]

In any case many thanks to you all for making time for me!!

Thanks E.Eye for reporting back! Excellent description.

• I can confirm that this was happening in 91.0.2 (64 bit), Win10, DE localization, exactly as described.
• Was maybe related to the spellcheck error below (which I think we've also fixed elsewhere), as saving shares code with sending, sending does spellcheck, and spellcheck may affect subject when it fails.
• As reported, problem is gone in 91.1.0 (64-Bit), Win10, DE, and the error also no longer occurs.

When we don't know what exactly fixed it, the bug is marked worksforme using the bug's status and resolution fields. We don't usually change the summary.

Uncaught 
Exception { name: "NS_ERROR_FAILURE", message: "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIEditor.getInlineSpellChecker]", result: 2147500037, filename: "chrome://messenger/content/messengercompose/MsgComposeCommands.js", lineNumber: 401, columnNumber: 0, data: null, stack: "updateEditableFields@chrome://messenger/content/messengercompose/MsgComposeCommands.js:401:38\nToggleWindowLock@chrome://messenger/content/messengercompose/MsgComposeCommands.js:2654:23\nComposeProcessDone@chrome://messenger/content/messengercompose/MsgComposeCommands.js:680:21\n_doFcc2/<@resource:///modules/MessageSend.jsm:962:12\nnotify@resource://gre/modules/Timer.jsm:62:17\n", location: XPCWrappedNative_NoHelper }
MsgComposeCommands.js:401
    updateEditableFields chrome://messenger/content/messengercompose/MsgComposeCommands.js:401
    ToggleWindowLock chrome://messenger/content/messengercompose/MsgComposeCommands.js:2654
    ComposeProcessDone chrome://messenger/content/messengercompose/MsgComposeCommands.js:680
    _doFcc2 resource:///modules/MessageSend.jsm:962
    notify resource://gre/modules/Timer.jsm:62

.

(In reply to Thomas D. (:thomas8) from comment #6)

[...]
When we don't know what exactly fixed it, the bug is marked worksforme using the bug's status and resolution fields. We don't usually change the summary.

Hello Thomas D.,
thank you very much for your feedback!! It is much appreciated and I will keep it in mind. :)
My apologies for causing additional work.