'-' dashes are not valid as part of a JIRA project key however, there are work arounds https://confluence.atlassian.com/display/JIRAKB/Project+Key+Patterns+with+invalid+characters.

When viewing the JIRA issue for stash for an issue key like BIG-PROJ-1, the JIRA dialog just shows a spinner.

There is a javascript error because the regex to extract the JIRA base url from the issue url does not account for invalid characters like '-'