Not running script because past shutdown deadline - datastore error?

Im getting that error, i have a bindtoclose function. I guess it doesnt work properly because when i press test and press stop it takes 30 seconds to unfreeze and gives the error

" Not running script because past shutdown deadline " x300

the bindtoclose function looks like this

function GetDictionaryLength(tab)
    local keys = 0
    for key,_ in next,tab do
        keys = keys + 1
    end
    return keys
end

game:BindToClose(function()
    repeat wait(1) until (GetDictionaryLength(sessionData) == 0)
end)