When you try to delete non-existing element, for example deleting same element twice, in result there should be error "ERROR: Cannot delete <object>" and in details "No permissions to referred object or it does not exist!"
And after error, there should be a list of other elements or empty table, if there are none. There are several places where there is only error message "ERROR: No permissions to referred object or it does not exist!" and the page just ends. It was mentioned in ZBX-7316 (1) that there should be list of objects after error, so all places should look the same.

The places this should be fixed are in configuration:

• applications;
• web scenarios;
• slide shows;
• user groups;
• users;
• media types;
• proxies.

There are several places with detailed error message "You do not have permission to perform this operation." instead of "No permissions to referred object or it does not exist!" when deleting a non-existing element. So in a way that first message is not true. The object might not exist.

Places where message should be changed are in configuration:

• templates;
• graphs and graph prototypes;
• maintenance;
• scripts (currently error details are "Cannot delete scripts. Script with scriptid "19" does not exist.", where 19 is current script ID, so probably it's best to unify this message also).