@jaosold . Open the website whose search engine you want to add. Long press the search query field and choose "Add search..."
This works with search engines that use an HTML form with the GET method. Most do but some like StartPage use POST or a JavaScript based form and can't be added to Opera.
@cypernisse Can you please visit http://www.sync.opera.com or http://www.auth.opera.com using opera for android and check the status if you are logged in. Also please confirm that when you go to Main menu -> settings -> sign in, you are not logged in?
Here is my suggestion:
Visit above mentioned site (http://www.sync.opera.com or http://www.auth.opera.com)
Clear site data by clicking on top left icon in address bar -> site setting -> clear data
Go to main menu -> settings -> sign in
Sign in to sync
@deargodjesusman This issue is fixed in our Beta version and will be available in our next major release. For early access to new fix and features, you may use Beta version.
@karamella101 apparently you are denied deleting this account on that level of your mobile.
If you want to delete opera, find and change administrator settings on your phone.
Search on startpage can help with instructions