You might be able to export all of them to IDML with Peter Kahrel’s Batch script:
https://creativepro.com/creating-batch-pdfs.php

…or try to find that plug-in? What is it?

I don’t know. If you’re using CC 2017, you might try disabling the GPU (in the Preferences dialog box) and see if that makes it smoother.

Well, Adobe dropped the price of InCopy to just $5/month per person… so that’s very reasonable for something that lets you edit the text. If you just need proofing, then there are many options out there.

Take a look at GoProof from Oppolis (https://www.goproof.net) or Tweak (https://www.tweak.com) or PageProof (https://pageproof.com)

Sorry, I’m not sure what the problem could be. Are you moving the files from mac to windows or vice versa?

Loic, sorry your reply disappeared. That sometimes happens on our forums. It was “held for moderation.” If it happens again, just email me and I will fix it.

Also, I edited your post above to use the “pre” html tags before and after, so that it appears correctly.

That is strange! Is it possible you are putting a Shift-Return after the last paragraph (instead of a proper return)?

This might work: ^[^.?!]+?:
The caret at the beginning means “beginning of the paragraph” and the caret inside the brackets means “not”… so this will find any series of characters at the beginning of a paragraph up to a colon, but not if there’s a period, question mark, or exclamation point between the start of the paragraph and the colon.