My accountant can not get into one of my company profiles. He has no issues with the other company user invites that I have sent

I can help ensure you've invited the accountant to the correct company, HIP Development LLC.

When you invite a user to your company file, they can only access a certain account where you added them into. This won't matter if you have multiple company files with the same login credentials. 

You'll want to remove your accountant and re-add him/her to access your company file. Here's an article for the complete steps: Invite an accountant to review your accounting in QuickBooks Online.

If the same thing happens, then let's check if the issue is browser-related. Please let your accountant log in to your file using a private browser. If they're able to access it there, then let them clear the browser's cache. You can also have them switch to another browser to do this task.

Keep me posted if you need anything else. I'll get right back to you.