On this, and on @jhull’s videos, I see a dropdown option on the Theme Browser. 
But my own does not have an option for making choices this way. I looked on Preferences and did not see an advanced option for turning this feature on. Is this just a PC feature?
Also, when I open Dramatica, I get a message from my computer that Dramatica is not compatible and will soon not be able to be used on my computer. Is there an update coming?
Two things,
On the tab where (above) is the word “Hamlet” you select the option “allow storyform changes”
The update is already out for 64-bit. They should help you out shortly.
What is the version number? I’m using 5.3.1 v66, but still got that message. [Check for update] tells me there is no update.
They have not responded. 
This is the email I got a few weeks ago:
Dear Dramatica Story Expert Client,
Summer is when Apple rolls out their newest version of MacOS, with announcements in early June, and delivery to the public in mid-to-late September. This new version of MacOS, 10.15 (called Catalina), will bring with it the biggest changes to MacOS in a decade: the elimination of ALL 32-bit “Carbon” applications, and the requirement that all applications running on 10.15 after September’s release be 64-bit “Cocoa” applications.
QUICK TAKEAWAYS:
Apple announced to developers MacOS 10.15 Catalina today June 3rd, and will release it in September;
The current Dramatica Story Expert 5.3.1 will NOT run on MacOS 10.15 (Catalina);
This summer we will prepare a free upgrade to Dramatica Story Expert 5.3 that will run on MacOS 10.15 (Catalina);
In July, August, and September, DO NOT install Apple's pre-release beta of 10.15 (Catalina) on your primary writing computer: Dramatica 5.3 will cease to run;
Wait until Apple's new MacOS 10.15 (Catalina) has stabilized and Write Brothers has shipped the free update to Dramatica Story Expert; (this will be at LEAST OCTOBER, possibly longer).
You are NOT affected at all if you are planning on staying with your current version of MacOS: "Sierra", "High Sierra", or "Mojave" (i.e. MacOS 10.12 through 10.14). Unless there is a compelling reason to install MacOS 10.15 (Catalina), we recommend you stay with your current version of MacOS.
Movie Magic Screenwriter 6.5 will also get a free update for MacOS 10.15 (Catalina), most likely in September, but definitely before Dramatica Story Expert.
THE DETAILS:
The Dramatica Story Expert that you are using is built on Apple’s 32-bit “Carbon” technology, but not for long. We intend to do a speedy conversion to a modern 64-bit Cocoa version over the summer, with a final, shippable version ready in the months after MacOS 10.15 (Catalina) ships in September. We expect this new 64-bit release of Dramatica Story Expert to support full Retina resolution, and other standards, such as MacOS Mojave “Dark Mode”, and full screen, among others.
We also expect this to be a FREE update to all Dramatica Story Expert 5.3 users.
What Do I Need To Do?
Nothing. Sit tight and do not install MacOS 10.15 until we have provided you with a new 64-bit version of Dramatica Story Expert. Apple will not release MacOS 10.15 (Catalina) until September, and even then we usually recommend all clients wait at least until the 10.15.1 (or 10.15.2) revision for Apple to get all their kinks out. Apple’s early bug fixing usually takes us into early October.
However, some users will be tempted to jump on Apple’s early public beta test versions of MacOS 10.15, which will probably become publicly available in July and August. IMPORTANT: If you choose to install Apple’s beta (pre-release) version of MacOS 10.15 (Catalina) before we ship the new 64-bit Dramatica Story Expert update, your current copy of Dramatica Story Expert will cease to run.
Write Brothers has been working closely with Apple engineers to port Screenwriter to the modern 64-bit standard, and it has been a long, slow process because Screenwriter has hundreds of professional features, many more than any other screenplay word processor. Dramatica Story Expert is expected to be a faster porting process than Screenwriter, because its user interface is more limited and because we are gaining valuable porting experience with the Screenwriter port. We expect that our new version will maintain full compatibility with your existing Dramatica story files.
We believe you’ll be happy with the results.
If you also own the current version of our screenplay word processor, Movie Magic Screenwriter 6.5, you should have received similar communications on the upcoming 64-bit update last week.
Expect further communications from us as we get closer to our own external tests late in the summer.
Best Regards,
Stephen Greenfield
President
Write Brothers, Inc.
I might’ve missed the Dramatica update that works with Catalina, not sure. Has it been released yet?
not that I know of. Hang in there.
Having mistakenly updated my Mac (or, rather, my Mac updated itself) I’m unable to open DSE. My “nearly finished” story structure is stuck in the software. I do have reports I’m able to reference, but they don’t answer all my questions. I’ve read posts on here and other sites about StoryWeaver. I have free time over the holidays and want to make the most of it.
So, my question: If I have already progressed 80% through DSE, would anyone recommend that I start over with StoryWeaver? Will I derive a real benefit from StoryWeaver, particularly in terms of finalising the story structure? Perhaps given that I have already worked out many details of the story, I could progress through StoryWeaver quite fast…
Do you/does anyone know if there “will” be an update?
Not me. I checked recently because I needed a new computer (I still have my laptop for Dramatica, but not sure how long that will last). I think I saw that Screenwriter has an Alpha release that works with Big Sur, which suggests that Dramatica could be in the works soon (?).
I used an older backup to retreat to a previous operating system, in the past, so I could use various software. That worked out ok. I have learned to keep the automatic update square unchecked, so it always waits for me to do it. (I use a Mac, too.)
As long as you’re on an Intel-based Mac, you can use VirtualBox to run Dramatica Story Expert. It is extremely clunky, but it does work.
(I don’t think that VM trick works for the new Apple Silicon Macs, which sets yet another soft deadline of sorts for Write Brothers.)