Why did Nazism appeal to many Germans and non-Germans?Is it because all Germans hatred for the Treaty of Versailles? I mean it did blame them for WWI.
The Treaty of Versailles did help drive Germans to Nazism, but it does not explain why non-Germans would have liked Nazi ideas. The Treaty explains why Germans were desperate, but it does not explain why Nazism (rather than some other ideology) appealed to them.
Fascism in general (Nazism is a form of fascism) appeals to people who are living in unsettled times and places. When there are economic and political problems, people want certainty and order. Fascism is all about providing these things. Fascism promises that everyone will be united and work towards a single goal. This would be very attractive to anyone who lives in a country that is undergoing problems and in which there seems to be no unity or common sense of purpose.
People took to Nazism, then, because the times were so bad in the late 1920s and the 1930s. They wanted the order and unity that it promised to bring. (And since many people were anti-Semitic, the idea of taking rights from Jews was not troubling.)