Regardless the source, such error is caused by merging segments across paragraph breaks. One of the paragraphs has contained an image before merging. After the merging the image/illustration is moved to another paragraph. Usually you could see that due to new tags appearing in such merged paragraph.

When merging segments across paragraph breaks you always should try to generate a target file immediately after merging to make sure this works. And you should also try to open such target file in Word immediately - because even if target will be created it is also possible, that Word will not open it anymore.

Hi Jerzy – thanks for the correct diagnosis, found your comment useful when searching for this. Just to check – is there no way, as far as you know, of undoing the incriminating merge? For example by dividing the segments again?

Undo does not work then—because Studio was heavily crashing after such operations, SDL decided to limit Undo and make it unavailable after segments have been merged over paragraph breaks. So you cannot undo the action.

Splitting segments does not restore the original file structure. When merging over paragraphs, two different XML nodes are brought together, so the resulting xml has a different structure. When splitting, the remaining node is split into two—resulting in even more changes in the xml. This is not an exact description, but a very simplified one. Nonetheless, splitting will not help.

Ah, you are right, I remember the crashing, and of course I’ve tried undoing now, in vain. I was hoping you might have a trick up your sleeve. A bit of a bummer that you don’t, as I am half way through a 5000-segment book.

I am torn between cursing Trados for all these little faults that add hours of work, and pondering in awe bout XML-node-level magic they must figure out.

Thanks for going out of your way to reply, Jerzy.

Well, there is a way out - as always. "Simply" start anew, possibly asking someone to pretranslate your file using perfect match or pretranslate from TM. Then, when merging segments, use this method: save file, merge segments, save target - when that is ok, continue. If not, close file WITHOUT saving, reopen, then use "Edit source" to bring the content of problematic paragraphs into the first one, translate this. In segments where wrong segmented text were add a space, change segment status to "Signo-off rejected" and lock.
Even if that reads complicated, it is not - it goes faster than you think. And this way you have a guarantee, that it will work.
The difference between edit source and merge is, that no segments are left empty.

Hey thanks! I am aware of most of these techniques, although I forgot about editing source. Thankfully this has not happened to me for a while. But this time I used another trick, and did a little regular expression find-and-replace of the source file in Word (search for [a-z] just after a paragraph mark), thereby getting rid of the need for merging.

I guess it’s the fact that I must take off my wordsmith hat and put on my “geeky programmer guy” hat that throws me off.

I am noting your tips, thank you.

Glad you've find your way around this reef.

In fact, a nowadays translator has to be not only a wordsmith, but—provided he/she is already one—needs to add a lot of extra skills on top of this. "Geeky programmer" guy is one of such

and I tried to add the file to the project again under a different name and now none of the files in my project are opening in trados. So, the regular trados shortcut: create the entire thing again...

Thank you!

I am not moaning, be careful with your language...

There is nothing intuitively indicating that I should do this. So, please be respectful a bit or dont write to my questions. 

I am quite respectful. And the fact you have to switch to the target language is known since adding files to a project is possible. It is not my fault, that you do not know the basic, but still post things like "So, the regular trados shortcut: create the entire thing again"–this is what I call moaning.

Sir, use that kind of language to the female family or relatives, Or your mother... not to people who just wasted 20 minutes here 10 minutes there to convince the software. You and I are never going to agree, so dont cross basic lines of respect. It cost me 30 minutes that is why I am frustrated, if it was intuitively available, I would have done it. I wont waste my time explaining like before. so, watch your language!

It is intuitively available, when using "Quick add files", which is present since at least Studio 2019.

If you don't know the very basics, but blame the software for your missing knowledge, you cannot mind an expert who gradually gets annoyed about such ignorance to keep the velvet gloves on! And Jerzy only said "moaning", HE DIDN'T INSULT YOU, you should be able to tolerate this and try to learn!

You instead shut up. We have a history and not a good one but always respectful until today. You wrote "shut up" end edited. Hush! you! I dont have time to waste like this. Shut up as you said. 

Seriously, stop writing please.

What do you mean with "a history and not a good one? Are you getting political, bah! Trying to discuss with someone like you is forlorn hope.