You know that comment is not going to solve anything.
Sadly, Britches won't be able to provide a save-game with the same problem as you.
Seeing it's a rare bug/problem: the ball is in your court. (you want your problem solved)
1. Tobs' first option: Uploading your zoo to the workshop.
The section that's important in that video starts at 1:36 and ends on 1:50
- tells you to click on "My Zoos" on your PZ main menu screen.
- Move your cursor over to the file of "name of your bugged zoo" and click "upload to workshop"
- Next screen, click on the "+" icon (not in video)
- Next screen, fill in a random title and click the green button "create workshop item" (not in video)
- Post the url for this workshop item on this forum
>What didn't work in those steps?
You were unable to try his second option, so no info on that one yet.
2. You already created a new sandbox zoo, with the same problem - so no point of doing that one again.
3. What did you try already? (most likely CM's or moderators already asked) but a yes or no is enough.
- Verify your steamfiles?
- Did you reinstall the game?
- Created a new franchise zoo and tried to get the quarantine building working in that mode?
- Tried the same in a scenario zoo - I know the Panda one forces you to use the quarantine building. Did the quarantine building work properly in that zoo?
4. Other questions
- How big is your savegame file in MB ?
You can always try to find someone to help you personally (friends/family/neighbors) to send your savegame to Frontier.
This is the best way to get actual help with your specific problem.