EA blocked by your broker?

If MT5 shows "AutoTrading disabled by server", your prop firm or broker has switched off EA trading on that account. Only their support team can switch it on. Most firms do it within a day when you ask.

First, rule out the quick fix

If the message says "disabled by client" instead, it is your own MT5: press the Algo Trading button in the top toolbar so it turns green, and make sure Allow Algo Trading is ticked in the EA's settings. No email needed.

Fill in your details

MT5 account number Server Your name

Email to support

Paste it into an email or the support ticket form. Copy the subject line first if they ask for one.

Subject

Short version for live chat

If they ask for more

Some firms ask for the EA's name or the file before they approve it. Answer honestly: it is KATANA, a risk-management EA, and you can send them the .ex5 file.
Check your firm's rules on EAs first. Some allow risk-management and trade-management EAs but not EAs that trade on their own.
Once they confirm, restart MT5 and attach the EA again.