We do not use per-project wikis and prefer to maintain collective wikis that may span across multiple projects. Because of this, the key for our JIRA projects often don't match the key for the space they are linked to (eg. shown is our JIRA Management project (JM) which is linked to the Facilities Management space (FACMAN).

When visiting the wiki (on any page) and using the drop down menu of projects in the left of the top menu block, the links to the projects should take you to their configured Confluence space but instead take you to a space referenced by the project key (eg. For JM, the link is /wiki/display/JM instead of FACMAN as it should be) resulting in a 404 if the space with that key doesn't exist.