A new macOS update is causing more problems than it fixes, with Mac users reporting a host of nasty problems — including bricked MacBooks.

"The 8 April 2020 Supplemental Update for Catalina 10.15.4 brought the system down for a few hours," said one poster on Apple's own discussion forums.

"WARNING macOS Catalina 10.15.4 Supplemental Update BRICKED my 13 inch Macbook 2018!" posted another user on MacRumors' forums.

"This bricked my 2019 MBP. Not providing power to devices either. Needs an SMC reset but won’t accept it," posted a third. "Be afraid, be very afraid. Timing couldn't be more brutal."

Other users reported that the download didn't work at all through the App Store.

This supplemental update for macOS 10.15.4 Catalina, released Wednesday (April 8), was meant to resolve issues created by the 10.15.4 update in late March.

That earlier update created issues with systems crashing during large file transfers, failures to wake up from sleep mode, unresponsive USB-C ports, random restarts and even kernel panics.

The new update may indeed fix those, but it seems to be making things worse. Until Apple sorts this all out, don't install the Supplemental Update for Catalina 10.15.4.

If you have done so and your machine is stuck or otherwise hangs, one poster on Apple's discussions forums might have found a way around the issue.

"I went to Recovery Mode, ran the Disk Utilities First Aid and then rebooted again," tim01 posted. "My screen came up and I was able to sign in."