1268681 - Some email messages unreadable because message contains only blue squares

Status: RESOLVED INVALID

(Thunderbird :: Message Reader UI, defect)

Description

[Nomis101]

Attachment: Screenshot of issue

I don't know what this is, but sometimes I receive messages which I can not read, because the content looks like in the screenshot. In total since now I have received 3 of those emails. I could't find any similarity in the source code of this three emails, so I don't know what the reason could be.
This is independent of the TB version.

Comment 1

[Jorg K (CEST = GMT+2)]

You should attach one of those e-mails here (or forward them to me directly). Does this happen in safe-mode with add-ons disabled?

In any case, I'm guessing that this is a CSS issue. If the CSS contained in the e-mail defines blue text on blue background, then this is what you'd get. If you can read CSS and HTML, look at the e-mail source.

Comment 2

[Nomis101]

Attachment: Email example 1

This is the email from the screenshot. I have tried to anonymize it.

Comment 3

[Nomis101]

Attachment: Email example 2

This is a second email, also anonymized.

Comment 4

[Jorg K (CEST = GMT+2)]

OK, when I look at example 1, I see mojibake: �V�V�FW'vVw2��� (https://en.wikipedia.org/wiki/Mojibake).
The blue squares seem to be the Mac equivalent.

Looking at the message source, which you can do yourself, I see that the plain text and HTML parts of the message are base64 encoded, for example:

Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64

U2VociBnZWVocnRlIEZyYXUgTMOkbW1sZSwNCg0KdmllbGVuIERhbmsgZsO8ciBJaHJlIEFuZnJh
Z2UgdW5kIEludGVyZXNzZSBhbiBkZW4gR2V3w7xyemVuIHZvbSBBbHRlbiBHZXfDvHJ6YW10Lg0K
DQpEYSBpY2ggZGllc2UgSmFociBpbkaWVuIHVudGVyd2VncyBrYW5uIGljaCBJaG5l
biBnZXJuZSBtZWhyIGRhcsO8YmVyIGVyesOkaGxlbiB1bmQgZXJrbMOkcmVuLg0KDQpEZXNoYWxi
IHfDpHJlIGVzIGFuZ2VicmFjaHQgd2VubiBTaWUgdW50ZXIgZm9sZ2VuZGVyIE51bW1lciBrb250
YWt0aWVyZW46DQoNCkLDvHJvOiAwOTM3MiA5NDgxMDkyMw0KU2llIGVycmVpY2hlbiBtaWNoIHZv
biBNb250YWctRG9ubmVycNyBVaHINClVuZCBGcmVpdGFnIHZvbiAgICAgICAgICAg
ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgOC0gMTMgVWhyDQoNCkZy
ZXVlIG1pY2ggYXVmIElocmVuIEFucnVmIC4NCg0KTWl0IGZyZXVuZGxpY2hlbiBHcsO8w59lbiBh
dXMgS2xpbmdlbmJlcmcNCg0KS2lsaWFuIEhvbGxhbmQNCkdlc2Now6RmdHNmw7xocmVyDQpBbHRl
cyBHZXfDvHJ6YW10IEdtYkggSW5nbyBIb2xsYW5kDQpVbnRlcmxhbmRzdHIuIDUwICB8ICBELTYz
OTExIEtsaW5nZW5iZXJnIGFtIE1haW4NCg0KVGVsLjogKyA0OSAoMCkgOTMgNzIg4oCTIDkgNDgg
MTAgOSDigJMgMjMgS2lsaWFuIEhvCkZheDogKyA0OSAoMCkgOTMgNzIg4oCT

Something has gone wrong here. The lines should all have the same length.

You can decode them here for example: https://www.base64decode.org/

The result is a disaster, since the input is corrupt.

The second message is equally corrupt.

Sorry, nothing we can do about this.

Comment 5

[Nomis101]

(In reply to Jorg K (GMT+2) from comment #4)
> The result is a disaster, since the input is corrupt.
> 
> The second message is equally corrupt.
> 
> Sorry, nothing we can do about this.

Wait, this is why I said "anonymized", I cut the code by myself so nobody can read it. This was just to show you an example how the emails are looking in general. 
The (real) emails can be read without problem on my iPhone, with Apple Mail and directly in Webmail.

Comment 6

[Jorg K (CEST = GMT+2)]

(In reply to Nomis101 from comment #5)
> Wait, this is why I said "anonymized", ...
You mean: Corrupted? ;-)

Anyway, you have the steps to pursue this further:
View the message source and decode it at https://www.base64decode.org/.

Alternatively, zip up one of those messages and send it to me directly.

Comment 7

[Jorg K (CEST = GMT+2)]

I received a zipped up message from the reporter. This displays perfectly fine on Windows in both TB 45 and TB 49 (Daily). Is the message you've sent me the one shows in attachment 8746775 [details]?

This seems to be a Mac problem.

Comment 8

[Jorg K (CEST = GMT+2)]

I've decoded the
  Content-Type: text/html; charset="utf-8"
  Content-Transfer-Encoding: base64
part at https://www.base64decode.org/ and saved the result as HTML (apart from the missing embedded image). Displays fine.

Comment 9

[Richard Marti (:Paenglab)]

Nomis, maybe your font to show the messages is corrupt. Could you try to choose a different font?

Comment 10

[Nomis101]

(In reply to Jorg K (GMT+2) from comment #7)
> I received a zipped up message from the reporter. This displays perfectly
> fine on Windows in both TB 45 and TB 49 (Daily). Is the message you've sent
> me the one shows in attachment 8746775 [details]?
> 
> This seems to be a Mac problem.
Yes, it seems so. I can open and read the same email with Thunderbird on Windows.

(In reply to Richard Marti (:Paenglab) from comment #9)
> Nomis, maybe your font to show the messages is corrupt. Could you try to
> choose a different font?
Thanks, this was a good hint. Using a different font did not help, but after removing the checkmark in the font control at "Allow messages to use other font", I was able to display the messages correctly.

Comment 11

[Jorg K (CEST = GMT+2)]

This is surprising since the fonts contained in the message are:
Calibri, Tahoma, Segoe UI Symbol and Times New Roman.

I have sent you the message body converted to HTML in a private message. Please open it in Firefox on the Mac and check whether this displays or not.

Comment 12

[Nomis101]

(In reply to Jorg K (GMT+2) from comment #11)
> I have sent you the message body converted to HTML in a private message.
> Please open it in Firefox on the Mac and check whether this displays or not.

It does not display correctly if I open this HTML file within Firefox 45 on Mac. But it does also not display if I open it in Safari.

Comment 13

[Jorg K (CEST = GMT+2)]

That's what I thought. Report a bug on FF.

Comment 14

[Nomis101]

(In reply to Jorg K (GMT+2) from comment #13)
> That's what I thought. Report a bug on FF.

So, you mean I should open a new bug for Core? And, is there a way to generate an example HTML file, like yours, which does not contain my private email message?

Comment 15

[Jorg K (CEST = GMT+2)]

Just remove private information, HTML is text. You won't destroy it like you did with the base64 ;-)