So, I bought Icewind Dale: Rime of the Frostmaiden a little while back, since I wanted to run it with a couple friends of mine, and I built encounters with the materials in the encounter builder, but I went to check it today and it's been removed from the content that I had. And I am POSITIVE that I've bought it.

Please, if you can spare some help, I would appreciate it (I've already checked the history and it's not in there, but Idk what's going on...)

If you check your marketplace records, are your entitlements in sync?  And does the book appear in your current product licenses?

I checked my marketplace and it doesn't seem to be there, which is confusing, because I know I bought it, but it's not showing up. And I was able to build encounters with it before, but I checked it today and it's missing. On another note, how would I sync my entitlements? 

The first thing on your Marketplace page should tell you if your entitlements are synced correctly, like this:

Account Entitlements
Your entitlements data is in sync! You should have nothing to worry about, but contact our Support Team if you're having problems accessing your purchased content.

It says that everything is synced and good, but I still can't access Rime of the Frostmaiden 

I double checked and I'm on the right account. For extra proof,  It has all my other materials as well as my characters for many of my campaigns. But it's confusing since I haven't left any campaigns and I have the master subscription alongside all the materials that I've bought yet I'm missing Icewind Dale. But I also have encounters that have already included some of the monsters from Icewind Dale in the encounter builder and I had bought the book previously, but it's not registering nor appearing in my marketplace purchases, although I have bought it and ran the modules with friends. And for that, I'm very confused ;-;

See if you still have the receipt in your email. If you can find some proof, you can probably open a ticket with support.

I took a look around in my email and I don't seem to have any of the receipts that I was supposed to have been sent. I might have to go put in a ticket regardless though, since this is a, somewhat worrying problem.

My guess is that you didn't buy it and were just having it shared with you which no longer is.

Is it possible that someone else in a campaign had Icewind Dale and it was shared with you, but now that campaign no longer has sharing?

Great minds, Naru! 🤣

That's what I originally thought, but I haven't left any campaign on my DND beyond campaigns. Not to mention, I haven't deleted any characters associated with any campaigns. So that's my current confusion. 

Quote from ArcaneLotus >>

That's what I originally thought, but I haven't left any campaign on my DND beyond campaigns. Not to mention, I haven't deleted any characters associated with any campaigns. So that's my current confusion. 

  It could be that whoever was sharing had their sub end without renewing. Or the DM just decided to stop the adventure being shared using content management. Have you checked with the DM / whoever was sharing?

That would've been my first thing I checked, but most, if not all the campaigns I'm in, I'm sharing the content that I've bought.. Which is confusing me heavily. Especially since I need to look at my players and see if spells got removed.

Quote from ArcaneLotus >>

That would've been my first thing I checked, but most, if not all the campaigns I'm in, I'm sharing the content that I've bought.. Which is confusing me heavily. Especially since I need to look at my players and see if spells got removed.

 Even if you are the one turning on Content sharing, it shares EVERYONE'S content within the campaign, so if you enable it, but someone else has purchased content, then this shares back to you. Content Sharing is not a person A turns on and only person A's content shares.

It may be that a player was in a campaign and was sharing the book and is now no longer? I checked your account and there is any purchase for the adventure.

Gotcha. I thought it could be that but I wasn't entirely sure. Thank you for clarifying and assisting with this issue! It's been really confusing for me recently!