See https://support.mozilla.org/en-US/questions/1316575

Doh! Didn't even think of that! I did that very thing for two other people, but I wasn't having the related issue at the time so I forgot about it.

Thank you very much, I'm sure that's it!

So, for the record, the fix above was not the solve for this particular problem.

To clarify, this issue that I'm having is in uploading files via FileLink in Thunderbird. The message is "Unable to uploaded FILENAME to WeTransfer." This problem only started a few weeks ago and it appears to be random.

Unfortunately, it's hard to tell who this problem belongs to. Sometimes wetransfer attach works, sometimes it doesn't. I disabled the ssl and rebooted and then finally disabled completely and the issue persisted. So I turned it back on. Then it started working fine - until it failed again. It is also not fixable by turning the firewall off as I said before, though it seemed to be at the time. And yes, I have a solid hi speed cable connection.

• With both the firewall off and ssl disabled in ESET, it still would not attach. Both are now enabled.
• Yesterday afternoon when I was trying to get deadline projects sent to the printer, I had nothing but failure
• This morning I was sending test emails and I couldn't get them to fail.
• Finally about 20 minutes later this morning, I tested again and I got the Upload Error. Then it failed on my next test 5 minutes later.

I have emailed ESET but they appear to be ignoring my email. :\ I am also writing to Wetransfer to report the issue. Perhaps this shotgun approach will get some answers.

If anyone has any additional insight, it would be appreciated. :) Thank you!

Does uploading directly via the WeTransfer website also fail?

Nope not at all - never have had an issue uploading directly.

Yesterday, that's how I got my large files to the printer when I realized it was failing again.

Wetransfer has been working fine as I've been writing this. Then it started failing again. I've just added dropbox as another filelink account.

I just attached a file with dropbox with no issue and then tried to attach the same file with wetransfer and it failed. I tried twice more and failed with wetransfer and immediately with dropbox again and it attached fine.

I wonder if it has to do with the verification that wetransfer now requires. That is a fairly new requirement, I think. ¯\_(ツ)_/¯

I had wetransfer entered in TB prior to that requirement and there is no way to enter any credentials or an authorization key or anything into the options in TB. Dropbox of course did require an authorization. Maybe?

Debbie

The suggested SSL setting fix did not work for me either. I thought that it was an ESET issue since disabling the anti-virus initially resolved but sometime later it was a problem again. :(

I'm hoping it will be resolved but using Filelink isn't a suitable option with WeTransfer at the moment.

I have the same problem and I do not use ESET. I created a cost-free account on wetransfer - just to avoid the dialog for the security code but the error is still there. Thunderbird seems to wait for something.... Direct sending files via Browser and Wetransfer works.

Same problem here. "Thunderbird + WeTransfer" not working.