Thanks for reaching out. I am very sorry you're experiencing trouble loading your documents. Can you try opening the document in a private or incognito window? Another common issue is the Operating System and the browser version. I would check that both of these are updated to the newest releases and not causing the issue.
If the issue persists, please send in a support ticket here with the following information in the body of the email:
1) Screenshot of the error message
2) URL of the document so we can take a closer look