"My YAPI is not Connecting" Troubleshooting Guide

Are you noticing YAPI is having trouble connecting to your workstation? YAPI relies on stable network infrastructure and not an internet connection on the workstation. However, the server will require an internet connection to make sure your license is valid. Failure to connect to the YAPI Service, the program that is running in the background on the server for YAPI, from a workstation would result in the following error:  


The purpose of this article is to be a guide with potential troubleshooting approaches related to frequently encountered connection issues.  

Tip: If you feel uncomfortable making any adjustments to your workstation or your network, contact your dedicated IT company.

How many workstations are unable to connect to YAPI?

One or two workstations cannot connect to YAPI.

All my workstations cannot connect to YAPI. 

Troubleshooting Single Workstations

Close and Open YAPI

Before attempting to try any of the following troubleshooting methods, attempt to close out of YAPI entirely on the workstation. From there, attempt to start up YAPI again. If the communication error persists, proceed with the following methods. 

Port Listening

A typical error that may occur during the connection process is that the workstation may need to confirm which UDP port it needs to listen on to get its initial connection. When introduced to the connection error, the following error will look like this: 


Click the Cancel button, this will introduce an additional pop-up window that will request which UDP port to listen to. The default port will be 18002, do not change this port number as this will be the default port set on the server for YAPI. 

Port Confirmation

Click the OK button. YAPI will attempt to reconnect to the server and the confirmed UDP port should be recognized by the workstation. If the issue persists, continue testing the next few methods. 

Network Type

Right-click the network connection Networkicon button on the bottom-right corner of the screen. From the list of options that appear, click on the Open Network and Sharing Center option.


The Network and Sharing Center window will appear. Things to confirm would be to see how the workstation is connected.

Network Type

If the Network type is coming up labeled as Public, this will also cause a connection error to occur as by default Public networks introduce restrictive Firewall rules. The network type will need to change from Public to Private.

NOTE: Certain Windows Operating Systems (OS) will separate this further as either Home or Work. Either of these two options are also acceptable. 

The process to change this network type will change depending on the Operating System (OS) of the workstation but the following guide should expand on how to adjust this setting for the most recent versions of Windows.  


Whether the office uses Windows Defender or more specialized software such as SonicWall or Sophos, the firewall ports will need to be introduced to the workstation and server for proper communication within the network. The YAPI Outgoing and Incoming Network Ports will list all the required ports for YAPI to function. It is recommended that the dedicated IT for the office introduce this list of ports as they will be aware of what proprietary software is being used at your location. After applying the ports into the active firewall, attempt to restart YAPI. 


Certain important components for YAPI may register as a false positive from Anti-Virus programs. What this may cause is a failure at startup even if the workstation is able to connect to the server. Depending on the program being used at your location, introduce the following folder and processes into the Anti-Virus Whitelist. After applying the whitelist, attempt to restart YAPI on the workstation.

Folders to exclude from scans


Processes to exclude from scans 



Troubleshooting Server

Inactive Service

If all the workstations are unable to connect to YAPI, a possible reason could be that the service is turned off. This could have occurred when YAPI fails to restart during a Service Reset or MySQL errors causing the service to crash. Restarting the service is actually quite easy, and can be accomplished through the YAPIService.

  1. On the server computer, click on the desktop icon labeled YAPIService or YAPIManager


  2. If the Start Service button is highlighted blue, it means it is currently not active. Click on the Start Service button and wait until the Stop Service button is highlighted blue instead.

  3. Attempt to launch YAPI on another workstation. If it continues to fail to connect to the server, proceed to the next section.

IP Address/NIC Card

If the server was improperly shut down or if the server uses a dynamic IP address versus a static IP address, YAPI will need to reestablish the IP address being used on the network. 

  1. Before configuring the IP Address, click the Stop Service button to safely configure the YService. Wait until the service completes its shut down and the Star Service button is highlighted blue.


  2. Click the Configure button on the top-right of the window. This will open a configuration window. 


  3. The Configuration window shows what IP address YAPI is going to be reading from. When launching the window, if the IP address was changed a warning window will appear showing that the incorrect IP address is in use. Click the Proceed button to confirm the current IP address. Then, click Start Service.

    NOTE: If your server uses multiple NIC cards, click on the Always use this network interface button. This will have the drop-down below become selectable and you can choose which NIC card is actively being used for the workstations on the network.


  4. Attempt to launch YAPI on another workstation. If it continues to fail to connect to the server, proceed to the next section.


This section will be the same as the Workstation version of the same name.


Similar to the Workstation version, however additional processes and folders will need to be introduced. As an additional step, after applying the whitelist, Stop and Start the YService on the server. This will apply the changes for YAPI the next time it becomes active. 

Folders to exclude from scans


C:\Users\*******\AppData\Local\Practical Dental Solutions\YService

Processes to exclude from scan

C:\Users\******\AppData\Local\Practical Dental Solutions\YService\yapipn\yapipn.exe

C:\Users\******\AppData\Local\Practical Dental Solutions\YService\yres.dll 

C:\Users\******\AppData\Local\Practical Dental Solutions\YService\yapipn

If none of these steps assisted in getting your YAPI reconnected, please immediately contact YAPI support so we can continue to assist.

Was this article helpful?
4 out of 17 found this helpful