When reducing the pricing plan to the PROFESSIONAL plan, there was a situation where you have an active feature Visibility Tree, which is not available in this plan. Therefore, it is necessary to deactivate the feature.
The Visibility Tree feature can be turned off by the administrator in Settings. Simply hover over the title Visibility Tree in this section, which will display the trash icon. Clicking on this icon will bring up a notification informing you that the tree will be deleted, but the visibility settings will remain intact. Finally, you need to click the Deactivate button, which will turn off the feature and allow you to proceed with the transition to the PROFESSIONAL pricing plan.