In T245694#5964346, @matmarex wrote:

"LINK TO WIKITEXT EDITOR"

I avoided including a link because it's always confusing to me when some interface has multiple buttons that do the same thing. I always get the urge to compare them and make sure they really work exactly the same. Is it just me?

@matmarex, can you say more what you mean by, "...some interface has multiple buttons that do the same thing."?

...as this is currently implemented [1], it looks like there is one button, "OK" that simply closes the dialog.

1. Current implementation for cases #1 & #3:
   

Copy changes

Case #1 & #3 (comments/discussions are wrapped in/"near" templates):

• Current copy: "This comment can't be replied to using this tool. Please try using the full page editor instead."

Revised copy
The "Reply" link cannot be used to reply to this comment. To reply, please use the full page editor by clicking "Edit source."//

Case #2 (an entire discussion page is transcluded from another page):

• Current copy: "This comment can't be replied to here (yet), because it is loaded from another page. Please go to SUBPAGE LINK to reply to it."

Revised copy
The "Reply" link cannot be used to reply to this comment because it is loaded from another page. To reply, please go here: [SUBPAGE LINK]().

Note: I assume "Case #2" will soon be made obsolete by: T247535

Rationale for changes
I think the changes above will help people encountering the error message better understand what action caused the error to appear and what steps they can take to accomplish what they were intending to.

Change 592461 had a related patch set uploaded (by Bartosz Dziewoński; owner: Bartosz Dziewoński):
[mediawiki/extensions/DiscussionTools@master] Revise error messages when replying to comments affected by templates

https://gerrit.wikimedia.org/r/592461

Change 592461 merged by jenkins-bot:
[mediawiki/extensions/DiscussionTools@master] Revise error messages when replying to comments affected by templates

https://gerrit.wikimedia.org/r/592461