问题
When I receive a remote notification on a record addition (didReceiveRemoteNotification called), I get the following error message:
_BSMachError: (os/kern) invalid capability (20)
I've already tried to find out more about this in forums and via Google but I could not find any helpful advice that applies to my situation.
What does the error message mean? What can I do about it?
回答1:
I just experienced this error. I was in a UIAlert Action block; when the block exited the error occurred (BTW the parent UIAlertViewController was created in a dispatch_async block so was I guess off main thread.
Anyway, I wrapped the action code itself in
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
[self handleActionForElement:thisType];
});
and error went away. Your mileage may vary!
回答2:
For Swift 5, I ended up with:
func alertAction() {
DispatchQueue.main.async {
//perform code
}
}
回答3:
Thank you very much, I had the same issue on swift
So I've resolved it by putting code in main thread
func alertAction() {
dispatch_async(dispatch_get_main_queue()) {
//perform code
}
}
回答4:
Had same issue. I was trying to present a custom view on top of a presented view controller of third party framework.
Resolved by moving the presentation logic to my view controller
来源：https://stackoverflow.com/questions/31720133/error-bsmacherror-os-kern-invalid-capability-20-after-receiving-remote-not