Can you tell me which specific build of ThingWorx 7.3 you have? If the page at least somewhat loads, you can access the version information through the "hamburger" menu in the top right corner.
Also, what login are you using for ThingWorx? Is it a user other than the default "Administrator"?
Finally, can you post a screen shot of what the console page looks like when you try to access it?
One possible thing could be user group assigned to the user. What group the user assigned to? You need the following from Manufacturing. Don't add Plant Manager and Quality Engineer. If you add, it takes out privilege (there is open ticket on that)
- Controls Engineer
- Maintenance Engineer
- Maintenance Manager
I would also Administrator to make the life easier for you.