Specifically, the users who own old and new models of Macbook with an outdated version of Boot Camp and drivers are seeing the warning about the particular message on Windows 10 Setup window. The full warning message is:
Fix – Windows 10 May 2019 Update not installing on Macbook
Microsoft will release the fix for the issue somewhere in July 2019. In the meantime, you can try a temporary solution to the problem to get around the block by updating to the latest version of Boot Camp. As mentioned on the Microsoft Support page, once you update Apple Boot Camp Windows Support Software driver, it is possible to get the Windows 10 May 2019 Update on Mackbook. To check for the latest version of Windows support software in macoS, you can select Apple menu > Apple Store and then download and install the latest updates available. For step by step instructions you can check this support article from Apple. Are you affected? Do you able to fix the issue using the above workaround? Let us know in the comments. Source – WindowsBlogItalia