Knowledge base

Knowledge base : Error Messages
Cause This indicates an endpoint (typically the host computer) was reached by the connection attempt, but that no service was running on the relevant port and hence the connection was refused. Commonly, this is because: * The service is not running....
Cause During the connection attempt, no response was received from the specified IP address, even to reject the connection. Resolution This error usually indicates a misconfigured router or firewall. If you are running any firewall software on the V...
Cause This generally suggests a network issue which is not related to the VNC(R) application itself. This could be due to network hardware being either misconfigured or faulty. Resolution As far as the application reporting the error is concerned, t...
Cause VNC(R) Server has a 'blacklisting' scheme that blocks an IP address after five unsuccessful connection attempts. The IP address is initially blocked for ten seconds, but this doubles for each unsuccessful attempt thereafter. Resolution A succe...
Cause You will receive this error when: * You try to connect to a VNC(R) Server that has encryption set to 'always on' from a VNC Viewer that does not support encryption * You are connecting from a VNC Viewer that has encryption set to 'always on'...
Cause This is one of the more common error messages reported, and the error itself does not give an adequate description of the actual problem. However, it is most often caused by one of the following: * Your "Hosts" filter has been deleted, or mis-...
Cause This error normally occurs because the VNC(R) Server PC has some internet security software operating that prevents the VNC Server software from binding to a port. Resolution This theory can be tested by disabling any Internet security softwar...
This article applies to the following product(s): VNC ENTERPRISE EDITION/VNC PERSONAL EDITION Cause This error is usually received because the Application Event Log of the VNC Server machine you are trying to connect to is full. When using Windows a...
Cause Winsock Errors are Microsoft Windows Sockets (TCP) errors, not VNC(R) errors, and ARE NOT DIRECTLY RELATED TO VNC SOFTWARE. This specific Winsock error implies some type of Name Resolution issue within the network environment. Resolution VNC...
Cause There are conflicts with both InnoSetup and MSI installers with resident security software/security scanner. When running the VNC(R) Server installer, you may receive the error: "An error occurred while trying to rename a file in the destination...
This article applies to the following product(s): VNC ENTERPRISE EDITION/VNC PERSONAL EDITION Cause Typically the most common cause of this error is that you are entering your username and/or password incorrectly. In the first instance, please check...
Cause This error means that VNC(R) Server has aborted the connection. The established connection was aborted in the host machine, possibly due to data transmission time-out or a protocol error. Resolution Please see the Application Event Log of the ...
Cause This error means that a socket operation was attempted to an unreachable network. It usually means that the local software (in this case VNC(R) Viewer) is unable to find a route to reach the remote host (VNC Server computer). It could suggest an u...
Cause This error means that a socket operation was attempted to an unreachable network. It usually means that the local software (in this case VNC(R) Viewer) is unable to find a route to reach the remote host (VNC Server computer). It could suggest an u...
In the first instance, check this FAQ: https://www.realvnc.com/docs/faq/connect-fail.html#why-can-t-i-connect [https://www.realvnc.com/docs/faq/connect-fail.html#why-can-t-i-connect] Please also check that the computer running VNC Server isn't configu...
Cause This error message suggests that the Application Event Log of the VNC(R) Server machine you are trying to connect to, is full. When using Windows authentication, VNC Server needs to be able to log authentication to the Windows Application event lo...
Cause Intel AMT's KVM functionality (ie VNC(R)) can only be used with the on-board Intel GPU; secondary graphical adapters are not supported (e.g. if you've installed a new Nvidia or ATI graphics card.). Resolution You'll need to ensure that the on-...
This article applies to the following platform(s): UNIX Cause This error indicates that the default font path built in to Xvnc is not valid on your computer. Resolution You can find out the correct font path by running the following command whil...
Cause This error literally means "The server name cannot be resolved", which suggests a problem with the provided hostname, internet/network connection or similar. Resolution Please double check what you are entering into VNC(R) Viewer, to ensure yo...
Cause This means that the xauth program was not found. This is needed to start a VNC(R) Server desktop, but is often not on root's PATH. You will need to add the appropriate directory to your PATH. Resolution When the software was installed, it will...
Cause This error message can mean two things: * You're trying to connect as a non-administrative user. * Your computer is running Intel AMT 5.0 or earlier. KVM (VNC(R)) functionality is only included in Intel AMT 6.0 and above. Resolution Pleas...
Cause On old distributions of PAM on Linux, authentication using system usernames and passwords when there is no root coprocess fails with the error "Either the username was not recognized or the password is incorrect". Certain VNC(R) Server functions...
Cause This error indicates that the network is lossy enough to fool the TCP checksum, but not the more robust AES checksum performed by VNC(R) Viewer. One definite cause of this error is the Broadcom NetXtreme II gigabit NIC which has a setting "Large...
Cause This indicates that no response was received from the specified IP address or hostname. Resolution It usually indicates an incorrect IP address or hostname has been entered. You should check that you are entering the correct IP address or host...
This article applies to the following product(s): VNC VNC ENTERPRISE EDITION VNC PERSONAL EDITION This page only applies to Windows machines. Cause If you receive a "Secure encryption key is missing or corrupt" error on Windows, you need to invo...
Cause You may see this error when attempting to start VNC(R) Server on Windows. It indicates that the Windows Event Log service has not started. Resolution Restart the service: * Start > services.msc * Navigate to the Windows Event Log service...
This article applies to the following product(s) running VNC(R) Server in Virtual Mode: VNC VNC ENTERPRISE EDITION VNC PERSONAL EDITION Cause VNC For license checking, each instance of VNC Server in Virtual Mode registers the fact that it is runn...
Cause When running the license wizard or vnclicense -add from the command line, you may see the error "XML error 0:0 Error: First Tag not found". This is likely to mean that the Windows Event Log service is not started. Resolution Restart the servic...
When connecting to an Intel AMT computer, you may see the following error: Error 0x80862505: Viewer requested an invalid pixel format This is due to the AMT computer's lack of support for certain pixel formats (anything over 16-bit depth) - the error ...
Cause This error can occur when the user's .vnc directory is created with root ownership instead of the current user's ownership. One possible cause of this is if the root user has been disabled or deleted. The root user account is used to store data pe...
This article applies to the following platform(s): MAC OS X Cause On occasion, the VNC(R) Server icon disappears from the system tray. When attempting to re-launch it via Applications/RealVNC(tm), an error "VNC Server has failed to launch" is shown ...
Cause VNC(R) Server needs to be able to read the MAC address of the computer for licensing purposes. Some virtualization software does not provide a MAC address for the virtual servers it hosts. Resolution You can verify that this is the problem by ...
Cause When connecting VNC(R) Viewer to VNC Server in Service Mode, you receive an error indicating "a login or fast user switch has occurred" and the connection is dropped. Reconnecting to VNC Server connects to the login screen. Resolution To resol...
Cause This error is shown if you try to license VNC Server on a computer with an invalid timezone. Resolution To resolve this error, ensure a valid timezone is set on the VNC Server computer, for example using the Microsoft tzutil.exe tool.
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