Dropdown problem

Look, help with the script for dropdown, everything seems to be correct, but in the inspector I drag it into the field of the script that is attached to an empty object and the screenshot shows what is happening.

An icon like a stop sign on the road, I tried to find the same problem, they said there might be a problem in the script, but that is, with the name of the field like try public Dropdown Drop or public Dropdown drop, but there is no difference, I just tried a method for it to write where the parameter will be value and the action will be performed using Switch, but it also doesn’t work, in the new project everything is the same, on another version of the editor it’s the same.

The problem is strange, it’s very urgent. Help me please!

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