In the Finder, choose Go to Folder from the Go menu, then enter the following path into the window that opens: /var/log/install.log Then click the Go button. In the folder that opens, an install.log file should be selected. Double-click that install.log file to open it in the Console application. Next, search for 'sudoers' (without the quotes). If you find any lines in that log file saying something about 'no valid sudoers' being found, you have a problem with your system that is interfering with the installation.

(Note that there may be other messages relating to the sudoers file that do not represent a problem.) Unfortunately, a damaged sudoers file is not an easy thing to fix, and the best way to do it is to simply reinstall the system. Make sure to make a good set of backups, just in case something goes wrong. Once you've done that, see the following: Follow those instructions to reinstall the system, skipping the section on erasing the hard drive. This will just install a new, fresh system on top of your current one, fixing anything that's broken (like the sudoers file). If you don't see any of these errors relating to the sudoers file, compress that install.log file (control-click the file and choose Compress 'install.log'), then send me a direct message, and attach the install.log.zip file that will be created on your desktop.

Sounds like we had a similar situation, so maybe my solution will help you. I finally called Apple support and they walked me through a bunch of steps including going into library and clearing caches and saved applications state.

Discover and Enroll Via Apple DEP, Network, and SCCM AD System discoveries Inventory and Reporting Hardware and software inventory from managed Mac computers, compliance settings reports, user log-on information, and software metering Deploy Application, Patches, and macOS Images Package and application deployment models, self-service applications portal, macOS deployment, and patch management Enforce Compliance and Security FileVault 2 full-disk encryption, enforce compliance via SCCM baselines, and macOS specific configuration items. Sccm client for mac.

Turns out Malwarebytes wasn't allowed to completely install so that was the problem. My computer works great after the call with Apple support, including Malwarebytes. The support guy I worked with told me Malwarebytes is what they recommend for use on Macs. I'd say give Apple support a call, I was surprised how helpful they were and what they had me do worked for me. Hope this helps. I don't mean to hijack this thread, but I cannot install on my MBP either.

I receive the same error message as the initial poster. The installer hands on 'Checking Authorization of Malwarebytes Extension.' And then alerts that it could not install. A few things: I had MLWB installed before and it worked without issue. However, I went to uninstall the 1.x version and accidentally used CleanMyMac to uninstall the wrong version. I thought, maybe it didn't uninstall everything successfully so I located and used the 'Remove MalwareBytes.pkg' file for Macs to remove any remnants, restarted, and I am still having the same issue. MPB running High Sierra 10.13.2 I do have a copy of the install.log that I am going to send you in a PVT message.

Just wanted to let you know here first. I'm afraid you can't have it both ways. You can't use such an old OS and expect to be completely malware free. I'm not at all familiar with IBM Notes, but can't you at least run OS X 10.8.5 with Security Update 2015-006 for Mountain Lion? With that said, the current version of Malwarebytes requires OS X 10.10 or above, so that's why you cannot install it. You can try to download and install Malwarebytes Anti-Malware for Mac 1.2.4 if still available, but it's less capable and I don't know how much longer it will continue to be supported with current definitions. Should still be available for download from.