user profile field manager

[fardamm]

user profile field manager

Hello
I wan the user tick the related checkbox fields at registration (list of academic course ) ,
I need more than 40 options for checkbox fields, but when I use multi-selection checkbox, I see this error : You may only specify up to 31 options for checkbox or select_multiple input types. You entered 40 options for this field

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when I use Multi-Selection menu, I see this error: You can not have duplicate options with this field type

please help me fix this problem
How can I create a multi-selection check box with more than 31 options?