Issues with Knowify and Sync Manager

Hello, stardell. 

There are a few requirements that QuickBooks imposes on any 3rd party application trying to access the company file. But before that, have you encountered a specific sync manager error? 
 

In the meantime, I've got some troubleshooting to help you get around the issue. However, I'd recommend consulting an IT professional for further help with the process and setup.
 

The following reasons why you encountered issues with knowify and sync manager are: 

• The QuickBooks sync manager is not updated, and recent updates are missing.  
• Your Windows firewall might be causing an obstruction leading to the intuit sync error. 

To eliminate the sync problem, let's perform the following solutions:  

You need to clear the settings of your sync manager to resolve the issue.

1. Check the folder location of the sync manager application to make sure the location is correct. For Windows XP, it should be located inside C:\ Documents and Settings\ \Local Settings\ Application Data\ Intuit\ and for Windows 7 and Vista versions, the location path should be C:\ Users\ \AppData\ Local\ Intuit.
2. Make sure you are signed in as an Administrator on Windows and clear all the sync settings of the sync manager.
3. Open the QuickBooks application and click the Help menu to select the Manage Data Sync option.
4. Select Clear Sync Settings, and in the confirmation window, type YES and press the Enter key.
5. After successfully clearing the Sync Manager settings, reconfigure it to get rid of the QuickBooks Desktop sync setup error.

Your firewall or internet settings might be interfering with the sync process, leading to the QuickBooks sync issue. 

1. Go to the Sync Manager folder and delete all the problem-causing files.
2. Re-install the QuickBooks Sync Manager and follow the on-screen instructions for a fresh installation.
3. Run the sync manager and try syncing your data again to see if the error code is dismissed. 

I'm attaching these articles about multi-user. These articles explain user and managing the company file access. 

• Hosting your company data in a multi-user mode in QuickBooks Desktop. 
• Install QuickBooks Desktop on a server. 

Please let me know how it goes by commenting down below. I'll be there to assist you. Keep safe.

I failed to say that the PC is running Windows11.

This issue surfaced today. It was running fine.

Other than changing the QB server to another computer, no other changes have been made.

what is the path to the Sync Manager for W11?

I have searched for it with no luck. Plus the Sync manager option from within the application is no where to be found???

Also, I have read that the Sync Manager was discontinued in 2016. Accurate?

You're correct, @stardell. Third-party applications can no longer access Sync Manager.

After that, Intuit Sync Manager for Desktop is also no longer available for Intuit applications effective May 31, 2016. I recommend getting in touch with your developer to check for any available options in syncing data with QuickBooks Desktop.

For more details about it, read this module: Discontinuation (Disco) of Intuit Sync Manager.

Also, check out our QuickBooks Desktop help page in case you have additional queries about data management.

Don't hesitate to reply to this thread to get more help with handling data or QuickBooks as a whole. We'll respond as soon as we can.