Please follow below troubleshooting steps.

1. Kindly uninstall the applications you currently use.

2. Install applications following links from email with MT4 details or select the appropriate link here (Windows - PC or Android Devices or iOS Devices)

3. After installing, open symbols tab.

4. Click add and select the MELiUS folder

5. In the MELiUS folder add '.m'

6. Restart the application and try placing a trade again