Yes, it's still the same, LisaAir.

QuickBooks Error 15243 usually appears when we're trying to update QuickBooks Desktop. There are many factors that can trigger this error, I've listed them below:

• A corrupted download or incomplete QuickBooks installation.
• Corruption in the Windows registry 
• Intuit FCS Service is not running.
• Anti-Virus is blocking access to download the latest file.

I encourage visiting this link to be guided in repairing your QuickBooks Desktop for Windows.

You can also perform the troubleshooting steps that I've listed below to resolve this error. Before diving in, let's make sure that we're using the latest version of QuickBooks and we've already secured a backup of your company file.

First, we'll have to close your QuickBooks, then enable the QuickBooks Desktop File Copy Service:

1. Press Windows+R keys together from keyboard to open Run window.
2. Type COMPMGMT.MSC then click OK.
3. Select Services and Applications, then click Services.
4. Scroll down then double-click Intuit QuickBooks FCS.
5. Click on Startup type and choose Manual.
6. Then click Apply then OK.

Once done, re-validate the payroll's service key to refresh the connection:

1. Select Employees from the top menu bar.
2. Choose My Payroll Service.
3. Select Activate Service Key. 
4. Click Edit from the Service Keys window
5. Hit Next, then wait until the process is done.

I would also recommend updating getting the latest payroll tax table update to help isolate the issue.

If there's anything else that I can help you with, please don't hesitate to drop a comment to this thread. I'll be right here to keep helping.