Marketo Tabs in SFDC are not working
When trying to access the Marketo Tab in Salesforce users are receiving an error message:

When trying to access the Marketo Lead Management Tab in Salesforce, users are receiving a different error message:

When trying to access the About Marketo Tab, users receive a blank page.
I have looked through all integration points, user permissions, and visualforce page security and I have yet to find anything! HELP!