An application error has occurred while processing your request- why am getting this all day today since this QB update.....

I didn't want you to have this kind of experience, @Kristenia.

We'll conduct a thorough investigation into this. To proceed, please share some details to assist us in fixing this situation. Can you please specify where exactly you encountered this error message in QuickBooks? Please provide the complete error message and a screenshot of your concern for easier identification of the root cause.

In the meantime, let's perform basic troubleshooting to see if it's a browser issue by opening a Private/incognito window or other supported browsers. The browser's cache and cookies become corrupted, causing problems accessing websites or files.  Refer to the following keyboard shortcuts based on your browser type:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Microsoft Edge: Ctrl + Shift + P
• Safari: Command + Shift + N

If the private browsing session works, clear the browser's cache so the system can restart. Clearing the cache will reboot the system, allowing you to work with clearing the stocked cache and cookies causing the issues. 

Also, you can check this article for details about the QuickBooks Online software functionalities: QuickBooks Online FAQ.

We'll be checking on you timely and make sure to sort this out as soon as possible. Take care.