Steps to Reproduce:

1. Have an Instance with several issues.
2. Search for issues and save it as a filter.
3. Click the Export button and choose Full Content
4. Click the Project Link.
   

Expected Result:
The link will be redirected to the Project Overview page.

Actual Result:
The "404 Page not Found" is displayed.

Notes:

• You could notice by hovering on the project link that rather than using Project Key it is using Project ID instead.
• In JIRA 6.1.7 the issue is not present.
• Could be replicated via JAC(https://jira.atlassian.com) filters.
• Quick test please try access this link: https://jira.atlassian.com/secure/BrowseProject.jspa?id=10240