Apache install is proving very problematic on latest MacBook Pro. I use Tomcat, which communicates with Apache using a very well-known module called jk_module (file name mod_jk.so) Until Monterey, by using csrutil you could turn off SIP and simply copy mod_jk into the same folder as all the other modules, but SIP no longer allows you to do this. Now your only choice is to place it in a writeable folder. So it now sits at /usr/local/libexec/apache2/mod_jk.so all by itself, and in httpd.conf I tell LoadModule where to find it. Problem (NOT solved): Apache won't start. And there is no log of any kind to give you a clue as to what is happening. There is nothing in system.log, and apache2/error.log hasn't even been created! After a day being mystified by this, I rediscovered apachectl -t, which I had forgotten about, which checks httpd.conf for you. And there at last I was told that I must code sign mod_jk.so, even though it is a piece of software that everybody knows and I didn't create. Should be a piece of cake code signing a file right? Unfortunately not. After two days of trying all I ever manage to get is: "internal error in Code Signing subsystem". In my travels into every corner of Google I found a couple of very detailed pages showing how to create your own Certificate Authority and then a Code Signing Certificate. Here is one of those links: https://www.simplified.guide/macos/apache-php-homebrew-codesign. Again all I ever got were error messages. I then thought, well I'm an Apple paid-up developer, surely I should be using the Developer certificate which I use to sign my apps instead of creating an authority and a certificate ad hoc. So I ran the following command to sign my file: codesign -d --verbose -s "Apple Development: A. Malcolm Warren (FV8Y5HRUQ8)" --force --keychain ~/Library/Keychains/login.keychain-db /usr/local/libexec/apache2/mod_jk.so The answer is always: "internal error in Code Signing subsystem" I have installed two intermediate "Apple Worldwide Developer Relations Certification Authority" certificates in my keychain - one of which expires in 2023, and the other in 2030, which I read about somewhere here in developer.apple.com. Where do I go from here? How can I get this file code signed?