# OPC UA Connection Faulted Issue

**URL:** <https://forum.inductiveautomation.com/t/opc-ua-connection-faulted-issue/82041>\
**Category:** General Discussion\
**Created:** [November 17, 2023, 12:43pm UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-faulted-issue/82041 "2023-11-17T12:43:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Aravind\_G](https://avatars.discourse-cdn.com/v4/letter/a/8e8cbc/32.png) [@Aravind\_G](https://forum.inductiveautomation.com/u/Aravind_G)\
**Post date:** [November 17, 2023, 12:43pm UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-faulted-issue/82041/1 "2023-11-17T12:43:17Z")

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HI,  
I'm facing opc ua connection issue, can someone help me with this

UaException: status=Bad\_SecurityChecksFailed, message=status=Bad\_SecurityChecksFailed, description=An error occurred verifying security.  
at org.eclipse.milo.opcua.stack.client.transport.uasc.UascClientAcknowledgeHandler.onError(UascClientAcknowledgeHandler.java:258)  
at org.eclipse.milo.opcua.stack.client.transport.uasc.UascClientAcknowledgeHandler.decode(UascClientAcknowledgeHandler.java:167)  
at io.netty.handler.codec.ByteToMessageCodec$1.decode(ByteToMessageCodec.java:42)  
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:510)  
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:449)  
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:279)  
at io.netty.handler.codec.ByteToMessageCodec.channelRead(ByteToMessageCodec.java:103)  
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)  
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)  
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)  
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)  
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)  
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)  
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)  
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)  
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:722)  
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:658)  
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:584)  
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:496)  
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:995)  
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)  
at java.base/java.lang.Thread.run(Unknown Source)

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 20, 2023, 11:59am UTC](https://forum.inductiveautomation.com/t/opc-ua-connection-faulted-issue/82041/2 "2023-11-20T11:59:12Z")

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This usually means one side of the connection doesn't trust the other side's certificate yet.

Is this a connection to a third party OPC UA server or to Ignition's built-in OPC UA server?