activity_fun_facts.xml Exception raised during rendering: java.util.Locale.toLanguageTag()Ljava/lang/String;

Hello,

There are a few things that could cause this.

1) There have been some issues with Android Studio and the Android SDK in the past, you could try updating to the latest versions of both Android Studio and the SDK(avoid API 22 and the preview API 22 for M as well as build tools 22, use 21 for all of these as there's a few other issues occurring with those that I don't know if they're fixed yet)

2) This stackoverflow post mentions that if you have string literals in your layout's xml, it could cause this issue and to fix it you just need to put all string literals in your strings.xml file.

3) This stackoverflow post indicates that you might be able to solve this by changing what you are rendering to(a common mistake being set to render for Android Wear devices when developing for phones/tablets). To change this just make sure there isn't a W in the API version that you are rendering for.

Please let us know if any of these fixed your problem or if you need more assistance. If one of these did solve your problem, please let us know which one so anyone having this problem in the future could try that solution first.