The error message indicates that you're trying to open a new Player instance when the previous one wasn't closed, which is forbidden on Roku. Roku allows only one Player instance at a time. To resolve this issue, you need to ensure that the previous Player is closed before opening a new one.

Here are the steps to ensure proper handling of the Player instance:

1. Stop and Close the Previous Player: Make sure to stop and close the previous Player instance before creating a new one.
2. Check for Remaining References: If the issue persists, it might indicate that the previous Video node is still active. Check for any references to it and ensure they are properly cleared.