had the same issue on my Mac - reverting back to 1.8.1 solved the issue and I can save the files. I could use V1.9.0 perfectly fine in the beginning until I installed the development tools. after that I got the error message.
Go to Finder. Then go to application. Find Chitubox. On my computer you can only have 1.8.1 or 1.9 in applications. Once you find Chitubox right click on it and select "show package contents". It appears that 1.8.1 has slightly different file structure compared to 1.9. Anyways if you look through the folders you should be able to find the files in question.
Does anyone have this file they care to share? When I last used Pro, this worked fine but I was using the trial version. I decided to upgrade today assuming ChituBox would still work. I paid for the the annual subscription only to find, I cannot slice due to this error.
Come-on Chitu people ... a fix that's 5 months old still needs to be run again... i.e. copying the AnyCubicPluginMac and the plugin.json files into the 1.9.1 'show package contents' to get files to print on an Anycubic Mono X... I do confirm it works circa Feb 21, 2022.