If Run is greyed out, something is blocking it and Visuals will say what. Bad inputs are caught before the run, not after the credits are gone.
How it tells you
The Run button turns off and names what is blocking it
Every card with a problem carries an amber badge. Hover the badge for the full list
The common blockers
A file is still uploading or processing
Run stays off while anything is still going up, and it names the file it is waiting on. Wait for the card to swap to the real asset.
Your audio or video input is too long
Many models accept a short input. If you feed a 199 second clip to a model that accepts 15 seconds, Visuals tells you the clip is 199 seconds, the limit is 15, and to trim it. Use the Trim control on the card.
Multi-shot durations do not add up
On multi-shot models the shot lengths must equal the card duration. The settings panel shows the shot total and offers a one click fix that sets the card duration to match. A mismatch is refused before any credits are spent.
A required input is missing
Every model declares which inputs it needs. If one is missing, the run stops and the message names it. Connect the start frame, reference, character, or control input the model is asking for.
There is no transcript yet
Anything that needs a transcript checks for one first, and tells you whether it is still coming, failed, or was never going to exist. Cuts used to run without one and hand you a result built from nothing.
Not enough credits
Runs check credits before they start, so a run that cannot finish says so up front rather than stopping partway. The upgrade dialog opens where you are, and your work stays on screen.
The model is turned off for your organization
If your organization has restricted a model, the canvas says so at the run button rather than failing halfway through.
When you change the model
Picking a model that does not accept one of your connected inputs remaps or disconnects those connections and tells you what it did, instead of leaving dead connections behind. Your aspect ratio may also reset if the new model cannot produce it.
If a run still fails
Failed generations state the real reason. If the model turned down your prompt it says so. If the file was the wrong shape it says that instead.
Credits are automatically refunded on every failure, including a generation blocked by a content filter. You do not need to ask.
A stuck generation is picked up and cleared on its own.