Troubleshooting notes

This a "FAQ" section, with some less important content cleared out from readme.

Upgrading from phel 0.15.1

Delete cache files rm -rf data/.cache/ after composer update. Following should be fixed:

Deprecation warning appearing on page with 0.15.1 (Phel repo issue):

Error Unknown(4437) found! message: "Since gacela-project/gacela 1.8: `Gacela\Framework\AbstractDependencyProvider` is deprecated and will be removed in version 2.0. Use `Gacela\Framework\AbstractProvider` instead.

Fatal error after updating to 0.15.2 (because of cached files):

Uncaught TypeError: Gacela\Framework\ClassResolver\AbstractClassResolver::createInstance(): Return value must be of type object, null returned in /srv/www/wordpress-one/public_html/wp-content/pl
ugins/phel-wp-wishlist/vendor/gacela-project/gacela/src/Framework/ClassResolver/AbstractClassResolver.php:151