It wasn't until Adobe blocked support for Flash in 2021 that it revealed the reason this didn't work post MacOS 10.10 Yosemite; the beginning of new area cutscenes. This can be fixed by doing the following.

1. Go to Finder and find Diner Dash: Seasonal Snack Pack in your Applications section or in a folder for MacGameStore. Right click the icon and click 'show package contents.'

2. The folder you're looking for is hidden for security reasons. First click on the Contents folder then resources and enter on the keyboard at the same time Command+Shift+. (the period key.) You'll see a lone new folder called 'Game.'

3. You'll find the base game which has all the info for the game to run. Like last time, right click. 'show package contents,' and go into contents. Now go to resources, assets, downloads, _default, and restaurants.

4. Each folder are the locations in the game; all of them have one folder called 'Comics' with a .swf file. You can either outright delete the folders or just the files themselves.

5. The only issue you'll have now is during the loadup with the same 'missing plugin' - I'm sure there's another file you can delete to outright skip it, but you can just click anywhere to skip it (it's probably just the game company logo.)

Now when you actually get to the game, it's great to see some challenge in Dash series, but at the same time, it's quite unfair. For example, there's new mechanics that require you to not only pick up a tool, but bring it back when you're done with it. It doesn't help when some customers suddenly stop needing the tool (to fix a mess, serve drinks, etc,.) and it messes up your system.