Hey,
i think you can follow the instructions provided by the ownCloud people here to remove that “index.php” from the URL:
https://doc.owncloud.com/server/10.5/admin_manual/configuration/server/index_php_less_urls.html
From what i know this “Development” category you have chosen should be used if you want to contribute to e.g. the ownCloud development or if you need help with writing an own app but your problem seems to be unrelated to such topics so i think the “Server” category could fit way better.
Maybe you could also create a new topic in https://central.owncloud.org/c/meta/6 and explain why you had chosen the “Development” category? I think this could help the ownCloud people to understand the reasoning behind this choice and maybe could also help to improve the forum so that users are easier able to chose the correct category.