Run qp query rff context in new thread then error

I run qp query rff context in new thread. But it is error. what is wrong i can do it ?

Exception in thread "Thread-26" java.lang.AssertionError: Assert failed: ((some-fn keyword? string?) driver)
at metabase.driver$the_driver.invokeStatic(driver.clj:97)
at metabase.driver$the_driver.invoke(driver.clj:97)

Solved, should not use the Thread class to create new threads, itself api support asynchronous call function, ignore the above problem