By default NextCloud has index.php in the urls, it’s not a show stopper at all but it’s good to have nice clean urls when sharing.
It happened to me few days back when i try to upload an image via WordPress media library over 1MB of size. WordPress would throw an error
PHP APC is cache module provided by pecl and can be install via pecl. I assume you already had installed pecl.
“Phalcon is a web framework implemented as a C extension offering high performance and lower resource consumption”.