The best part about being a celebrity is having the oppurunity to travel worldwide and visit all countries in a glamorous way (private jets, fancy resorts, etc), but it is not always as magical as we think. Sometimes, things happen, people get offended, and then bam! They are banned from the country.
The complications that happen could be a misunderstanding since cultures and traditions could be disrespected unwillingly, it is only because the celebrity didn’t know better. In other situations, the issues get deep with the government, which leads to a complete ban from entering the country.