this is on a local server/singleplayer btw. Specifically, No Mercy, Death Toll, Dead Air, and Blood Harvest have no intro dialogue. Crash Course is fine, and all the L4D2 campaigns seem to be fine as well.

I've tried L4D1 campaigns with my vocalizer and ChimiChamo's Talker Things Collection enabled and intros played without issues. Do you have any error messages in console related to VScript? That could help identifying the cause of the problem.

Thank you for checking on your end.

I went through and enabled things one-by-one, and it seems to be some sort of conflict with Mayo's Modified Talker. Do the intros play their voice lines for you with this talker enabled?

You are right, my vocalizer together with Mayo's or Beel's talkers makes intros in L4D1 campaigns not to play.

The exact reason for this is that these talkers recently introduced new rules for situation when campaigns don't have intros. In that case, players will be able to start using vocalizations after 20 seconds. On campaigns' 2nd and later maps without intros, players will be able to use vocalizations after 5 seconds. This is only useful on custom campaigns since all official campaigns do have intros, and when players don't have my vocalizer. If players have my vocalizer installed, new rules are unneeded since vocalizations will be available immediately on map loading, regardless if it's 1st or later map in the given campaign.

By the way, these new rules have been proposed on GitHub some time ago for inclusion in official talker. But knowing Valve, they might be never included or it might take a long while. It can even change in the process. But even then, I'll consider to release a vocalizer update to "support" (better phrase: override) these new NoIntro rules.

引用自 ion：

You are right, my vocalizer together with Mayo's or Beel's talkers makes intros in L4D1 campaigns not to play.

The exact reason for this is that these talkers recently introduced new rules for situation when campaigns don't have intros. In that case, players will be able to start using vocalizations after 20 seconds. On campaigns' 2nd and later maps without intros, players will be able to use vocalizations after 5 seconds. This is only useful on custom campaigns since all official campaigns do have intros, and when players don't have my vocalizer. If players have my vocalizer installed, new rules are unneeded since vocalizations will be available immediately on map loading, regardless if it's 1st or later map in the given campaign.

By the way, these new rules have been proposed on GitHub some time ago for inclusion in official talker. But knowing Valve, they might be never included or it might take a long while. It can even change in the process. But even then, I'll consider to release a vocalizer update to "support" (better phrase: override) these new NoIntro rules.

interesting, glad to know why this was happening. thanks for investigating!

Also, you can check out my comment on Mayo's talker if you're interested in some more details about the situation.