新規作成画面に入力項目が何もない

• Page layout for new record is completely blank

UPDATE: I had two dynamic forms on my Lightning Page with similar fields, and a visibility filter based on one of those Fields. I moved overlapping fields to a generic section and was able to create the record from the New button.

更新: Lightning ページに同様の項目を含む 2 つの動的フォームと、それらの項目の 1 つに基づく表示フィルターがありました。重複するフィールドを汎用セクションに移動し、[新規] ボタンからレコードを作成できるようになりました。

• While creating an new Opportunity and Contact Role, I am unbale to crate or enter the details?

こっちは編集画面

• "Edit" and "Clone" Buttons not working on opportunity (certain record type)

no display contact Layout

• no display contact Layout

Could you check following things:

Field level security of Contact Object
Do you have proper permission sets?
Check Profile -> Object Level Settings -> Make sure fields you need to use have Read & Write access.
If above things do not help to find the issue, clear your cache and try again