@woland Thanks, the reexporting with iMovie resolved the issue.

@dusx

Thanks for your help. The problem I've run into is that the decklink outputs and the 4090 and 3070 are numbered the same. The 4090 and 3070 are numbers consecutively but the decklink has the same numbers. So if I assign display 2 to the decklink one of the other cards also has the same number. I just have display 1 thru 8 not 1 thru 16. I'm thinking about running two instances of Izzy one for the decklink and one for the nvidia cards. Btw the nvidia cards work very well with Izzy.

@cacoos

1. JSON Bunder and JSON Parser actors can be used to reduce the number of inputs you need.
2. Depending on how many instances of the User Actor you need, you could also use Broadcaster/Listener and/or Set/Get Global Values actors to get some of the information into your User Actors

@Cacoos wrote:

 I did not encounter this limitation in the previous versions I used.

I just tried in Isadora 3.2.6 and saw that I can't add 256 inputs there either. What version are you referring to? (Just asking because if we can pinpoint the last version where it did work, we can see what changed about this in the next version.)

@cacoos said:

My project requires 253 signal inputs plus one reset input, for a total of 254 inputs in a single User Actor or Macro.

 I would recommend bundling your similar parameters into JSON. I do this all the time for inputs/outputs. It can really make connecting things A LOT easier.

see: Using the JSON Parser and JSON Bundler Actors : TroikaTronix

Subject: 235-port limit in User Actors and Macros — Isadora 4.5.1 freezes when adding more

Hello Isadora Support Team,

I am experiencing an issue when adding a large number of User Input or User Output actors inside a User Actor or Macro in Isadora 4.5.1.

I can add up to 235 inputs or outputs, but attempting to add more causes Isadora to freeze. I did not encounter this limitation in the previous versions I used.

System configuration:

• Isadora 4.5.1
• MacBook Pro with M5 Max
• macOS Tahoe 26.5.2

Steps to reproduce:

1. Create a new, empty project.
2. Create a User Actor or Macro.
3. Add User Input or User Output actors inside it.
4. Attempt to exceed 235 ports — Isadora freezes.

The issue occurs even in an otherwise empty Macro, with no JavaScript actor, OSC processing, or other logic inside. This suggests that the problem is related to creating or managing the ports rather than processing incoming data.

My project requires 253 signal inputs plus one reset input, for a total of 254 inputs in a single User Actor or Macro.

Could you please clarify the following?

• Is the 235-port limit intentional, or is this a bug in version 4.5.1?
• If it is intentional, why was this limitation introduced, and can it be increased?
• Does the limit apply separately to inputs and outputs, or to their combined total?
• Is there a supported way to use 254 inputs in a single User Actor or Macro without freezing?

I can provide a minimal test project and a screen recording demonstrating the issue if needed.

Thank you for your assistance.

Best regards

@dusx said:

You will need to open your preferences folder, and delete "com.troikatronix.isadora.vst3-plugins.json"

Just for folks who run across this post in the future, it's worth noting that you need to go to Mac HD/Users/[YOUR USERNAME]/Library/Preferences 

Apple, in their infinite wisdom, has both of the following and they're completely different:

Mac HD/Users/[YOUR USERNAME]/Library/Preferences 

Mac HD/Library/Preferences 

@theuhleese said:

there is no file called "com.troikatronix.isadora.vst3-plugins.json" in my Preferences folder (Macintosh HD / Library / Preferences)

You need to go to Mac HD/Users/[YOUR USERNAME]/Library/Preferences 

Apple, in their infinite wisdom, has both of the following and they're completely different:

Mac HD/Users/[YOUR USERNAME]/Library/Preferences 

Mac HD/Library/Preferences 

@tomthebom

Try re-exporting the video file from another software or converting it. Some software bakes in a timecode track, (which Isadora can't use but which still causes issues in Isadora for some reason).

@tomthebom

Without seeing the actual video.... some troubleshooting thoughts:

Are you using the MBP in your sig for this show? If not, what system are you running?

When you say 'mess with Isadora' what do you mean? How does it mess with Isadora? What actually happens?

Does the video play fine in other software? iMovie, etc etc?

How was the video originally encoded? What format? What Codec? What frame size and rate? 

What did you 'resample' it to? And how did you do that?

I am doing some video mapping for the local theater. The given video turns out to mess with Isadora. I resampled the video without success. I had a complete reinstall of Izzy + deleting all old prefs. What are my options? See enclosed video for details.