Hi,
A few months ago I have developed a solution that uses your API and all was working perfectly.
Today I see that I throw a lot of com.dropbox.core.BadRequestException and it doesn't work as is should.
I have made a simple test where I display the folders/files from the root directory and also doesn't work. I even try the example from your repo (https://github.com/dropbox/dropbox-sdk-java/blob/c6aeb4bf3011e6b803eaa325ea20a52f8412ee0f/examples/tutorial/src/main/java/com/dropbox/core/examples/tutorial/Main.java#L32) and the result is the same.
There are some problems with your APIs?