That sounds to me like the interference Avast causes with it's poor anti virus scanner. But you say you reastarted in safe mode and still saw the issue. I think you should try again and see if you do see the error message when you click reply.

• Restart Thunderbird with add-ons disabled (Thunderbird Safe Mode). On the Help menu, click on "Restart with Add-ons Disabled". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender.
• Restart the operating system in safe mode with Networking. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, OSX

If safe mode for the operating system fixes the issue, there's other software in your computer that's causing problems. Possibilities include but not limited to: AV scanning, virus/malware, background downloads such as program updates.

Hi Matt,

Yep, I've done all of those things several times in the beginning, months ago, when many were looking for help on this issue. Then I decided to give it time and check back.....but that apparently isn't helping either.

AND I did all those suggestions again just now, even tried putting an image from my HD and got the SAME error message while in safe mode - arggggg!

Nope no antivirus running.

Can you tell me what TB version still allowed images, maybe I can just go back to something that worked.....

The problem is not Thunderbird. I have it installed and have had every version from 2 to 65 installed. ALL ALLOW IMAGES WITHOUT AN ERROR. So we must be seeking something that is unique to you.

So Could you please do the following:

1. Open the menu > Help > Troubleshooting Information, then click Copy text to Clipboard.
2. Go to https://pastebin.com and paste the info from your Troubleshooting Information page, then copy the resulting URL.
3. Open a reply to this post, and paste the link to your troubleshooting information.

What anti virus do you use? What exacly are the file names that you get the error attaching, and their path if one is given.

I've also - Set my TB to no proxy after reading this... Finally! It was set on Use System Proxy Settings... changed to No Proxy and the images are back! Thanx for your suggestion - I wouldn't have thought of that one  :o)

AND this - 'View' > select 'display attachments inline'

AND turning Autosave off....

Again what anti virus do you use. My Windows system is set to use system proxy and has been for a decade. Knowing which anti virus modifies the system proxy to make this mess would be quite helpful. But my guess would be Norton.

OK Matt, it is Done :D

Here it is: https://pastebin.com/xCj1tRdg

No not Norton, I was using SUPERanti Spyware & CCleaner

A while back I tried out Malware bits, but didn't like it.

I'm fine with the issue not being TB.... but that is where the error message shows up.

And I've just tried anything I read where other's solved their issues with images.

I appreciate your help,

Matt said

The problem is not Thunderbird. I have it installed and have had every version from 2 to 65 installed. ALL ALLOW IMAGES WITHOUT AN ERROR. So we must be seeking something that is unique to you. So Could you please do the following:

1. Open the menu > Help > Troubleshooting Information, then click Copy text to Clipboard.
2. Go to https://pastebin.com and paste the info from your Troubleshooting Information page, then copy the resulting URL.
3. Open a reply to this post, and paste the link to your troubleshooting information.

What anti virus do you use? What exacly are the file names that you get the error attaching, and their path if one is given.

You know :D there is a delay in our postings.....

The file names are different of course, if they are my saved files then they are the names.extension I've given. If they are a copy and paste, TB makes up a name. No path is given.

I've tried double clicking a broken image box - and no properties show, no file path, no file name. If I remove the troublesome image sending the message works :) no more error.

I hope this helps,

Do you think uninstalling and reinstalling would help?

Thanks for the additional information. I think as far as you are concerned it is fixed. Unless you install a VPN for some reason you are most unlikely to ever actually use a system proxy. They are really a business thing that are regularly subverted, either by anti virus programs or the malware they purport to chase.

But for the average home user no proxy is the same as system proxy, as the system does not have a proxy.

Hum.... no I just tested and it is not fixed.

I re-selected System Proxy, but turning that off didn't help my issue either. My issue isn't with 'proxy's' I just read to try that and I did.

Did you view my Pastebin? You asked for it, but haven't mentioned using it....

I still need thoughts-ideas, anything to try and fix this.... I'm glad you have never experienced this, but in doing my searches many people have - usually those who have a auto signature with a image.

Lots out there about this so it's not just uniquely me.

re : CCleaner

Be aware that CCleaner can remove files from your profile name folder. Such as session files and password files etc. It can mess up previously set settings. I would recommend you do not allow CCleaner or similar products access to Thunderbird folders.

Thank you for that reminder....

I'm very careful with CCleaner just for that reason. But something has happened, and I'd love to know what I should do to get back to the TB greatness I've enjoyed for so long.

Still looking,