Comment # 12 on bug 1227486 from Fabian Vogt

Did the manual kmozillahelper invocation trigger the error as well?

(In reply to ell1e from comment #11)
> I just noticed the error message shows "Mozilla Thunderbird", this can be
> seen in the video I attached as well.

That's normal, kmozillahelper tries to fit in there and calls itself either
Mozilla Firefox or Mozilla Thunderbird.

> Is it possible that this is supposed to be some misguided Thunderbird
> feature instead, where it looks up links before just opening them in the
> browser?

Theoretically possible, but the error message is definitely from KIO.