There is one common thing on all machines (6): The following updates never have worked (updated):
All PCs have been updated religiously, both the OS and Quickbooks and no server events happened overnight, nothing was updated or rebooted, no machines crashed, no power outages, etc. Because the payment service has crashed many times before in Enterprise over the years, it may have corrupted the file (in some fashion). This completely rules out the Network as the culprit and the problem squarely lies with Intuits merchant service. Then I copied the company file to a computer to completely eliminate networking as the culprit and tried to login again w/ the admin account: same error (or lack of). Tried again with the original company file (as an admin) - same result (from any of the 5 machines - ruling out networking, the computer and the installation). For good measure I disabled the firewall, A/V etc and ran the tool to verify the installation was fine. I loaded a different company file as an admin and it worked perfectly. Called me up, and I tried to login as the admin for that company file, and immediately after the icons are drawn at the top, a message box pops up saying an error occurred and to send a report to Intuit. He went through the steps, it said it was fine, and he was able to login, however, any time he attempted to enter a payment, Quickbooks would simply crash. In this case, the corruption (if there is actual corruption, though all tools report the file & network to be fine) was due to the QBUser server service stopping on its own, then a person tried to login in the morning and got an error message (for that), so I restarted the service, then he tried again, this time he got an error saying he needed to repair the file. Be sure to keep me posted on your progress with this.
Feel free to ask any questions you have here in the Community as well. If you feel that you need help with any of these steps, you can reach out to the Customer Care Support team here. If you're still encountering the Unrecoverable error, I have an article for you that covers general troubleshooting steps for Unrecoverable errors. Scroll down on the list and double-click QBCFMonitorService to open the Properties.Press Windows+ R On your keyboard to open the Run window.Prevent QBCF Monitor service from re-starting on the workstation.Select QBCFMonitorService.exe. and click End Process.On the Processes tab, click the Image Name header to display the processes alphabetically.Press Ctrl+ Shift+ Delete on your keyboard to bring up the Task Manager.
Since you've already tried installing on a different computer and you're receiving the same results, I recommend trying to disable the QBCF Monitor Service.
This can be caused by the QBCF Monitor Service or the QuickBooks Installation itself. There are a few steps available for this specific type of Unrecoverable error. I'd like to share with you some insight I have on this issue.