I have a member who can't do image attachment uploads in Safari on a Mac to my XF 1.5 forum. She can upload fine in Chrome, but from Safari (latest version) in OS X (latest version), when she goes to select the image for upload she gets the spinning beach ball and Safari becomes unresponsive.
Clearing browser cache/cookies/history and disabling browser extensions didn't help.
She just added the following info:
When I tried another upload I looked closely in Activity Monitor at all the processes running and found that there was one quite a ways down in red titled "com.apple.appkit.xpc.openAndSavePanelService (Not Responding)" it was taking up 99.8% of CPU and when I forced that process to quit, the frozen Safari dialog box disappeared and I had control of Safari again, though whenever I try again to upload the process reappears in red with (Not Responding).