This ticket is for creating the UX design for when errors occur that interrupt the user's workflow and don't have any corrective action.

For example, you open your private conversation with someone, but it just closes again (or shows an error message) because an error occurred while loading it. You open a private group, but when finding out whether it is dissolved an error occurs, so it stays in the disabled state by default. Or you are in a multi-step process and an error prevents you from reaching the next step like when creating a private group fails and you are not getting to the next step of inviting contacts to it.

Errors while loading blog posts, private message, forum posts, contacts, basically anything in lists falls into this category.

Subticket of #469.