@fnkkio, I'm wondering if this is an issue in the first place, as long as it works properly and opens all links from the folder...
If it works "properly" then perhaps warning could be sufficient.

I agree, it's only an issue of sorts if nothing happens.

@Emdek @Frenzie
It does not open all webpages, it opens a webpage with the url: bookmarks:x (where x can be 0 / 1 / ...).
I should have been more specific in the description.

Also, in my opinion, even if it opened all webpages in the folder, it wouldn't make much sense since we have session for that.

But what does that webpage show? Does it display the folder?

@Frenzie It does not display anything.

Added video demo in first comment.

In the meantime I've reached a computer. ;-)

I think the correct behavior would be something more like this (as a separate tab):

Or perhaps rather like this:

Disallowing folder selection is of course an easy way out.

@Emdek @Frenzie

Verified this issue again: This only happens when the bookmark folder is no longer available; if the bookmark is available, it will ask to open all bookmark URLs in folder.
(As a side-note this happened to me because I was importing bookmark and because of an issue, bookmarks were not stored between application restarts).

If this is ok / the expected behaviour, then we can close this issue.

I'd say it should display a little error message about folder not found then. Sounds like the functionality is good. ;-)