Please, be more specific
When posting about errors, please, be more specific.
Tell us exactly the text of the error, when do you obtain it, with wich emulator and version, your specs, and every information that may help us find the cause of the error.
In general terms, when reporting errors, bring all the information you can, because we don't know anything about you, your system, your software and hardware, and so.
A good practice is to write exactly the text of the error, and attach screenshots when no error text is available.