I ran across the need to disable Zend OPcache when working with Laminas API Tools in PHP, which was formerly called Zend Framework’s APIgility. In addition to requiring PHP Unit, you have to disable Zend OPcache to create a working API. Zend OPcache is bundled with many PHP installations to improve performance. In development on our local computers, we need to turn this off if we want this tool to work!
Check the php.ini. It looks off, but obviously it is actually enabled.
Disable all opcode caches when running the admin!
The admin cannot and will not run correctly when an opcode cache, such as APC or OpCache, is enabled. API Tools does not use a database to store configuration; instead, it uses PHP configuration files. Opcode caches will cache these files on first load, leading to inconsistencies as you write to them, and will typically lead to a state where the admin API and code become unusable.
The admin is a development tool, and intended for use a development environment. As such, you should likely disable opcode caching, regardless.
When you are ready to deploy your API to production, however, you can disable development mode, thus disabling the admin interface, and safely run an opcode cache again. Doing so is recommended for production due to the tremendous performance benefits opcode caches provide.