Hi there, artamous.
The login process requires a working built-in browser, which is responsible for online communication in the background of QuickBooks. Any updates to your computer system can make it obsolete and affect its functionality. This could be why the login process won't go through.
Normally, updating QuickBooks would resolve communication issues. However, as there are no more updates available for version 2018, I'm afraid I cannot provide any additional troubleshooting steps for this particular issue.
You can consider purchasing the latest version, so you can continue working on your company files. Just contact the phone above beside your Community avatar to buy QuickBooks. Then, you can follow the article about updating your company files to a new version later on.
Please don't hesitate to reach back out if you need further assistance with your company file. Take care and have a good one
