Check console or network tab as it maybe occurring while getting all payment methods on checkout page, also check logs if it is written there.
firs for all video is not attached to ticker.
Please remove all log before click on place order and then click on place order and you will see log related to your error.
if still not find then let me know so i will find respective file and tell you.
showing error in this file
try to read the error, it must give you exact error with line no. !