That message usually comes from the risk limits configured on the prop firm side, not directly from Tradovate itself.
Most prop firms enforce rules like:
• maximum contracts per order
• maximum position size per instrument
• scaling rules during challenges
In your message it looks like the account was limited to 1 contract for NQ (Rule #555), so when the order quantity exceeded that, the platform rejected it.
The usual fixes are:
• reduce the order size to the allowed quantity
• request a limit increase from the prop firm
• check if the rule applies per order or per position
This type of issue becomes even more common when traders run multiple prop accounts or copy trades across accounts, because each account can have slightly different limits.
When building multi account execution workflows we ran into this quite often while working on Proteryx.com. One thing we added there was the ability to enforce per account maximum quantity rules when copying trades across Tradovate and prop firm accounts, so the system adjusts the order size automatically instead of triggering rejections.
In many cases the root cause ends up being a prop firm risk rule rather than an order routing issue.
You may want to check the account risk settings or scaling rules tied to that challenge account.