Communication problem - blocked me - any suggestions are welcome


I frequently met a problem as the following:
There is a progress icon displayed in the top-right corner for a long time, and the application looks like “hanged”.

After I freshed IE, a message displayed:
Communication problem
Take note of any unsaved data, and click here to continue.
(SyntaxError): Syntax error number: -2146827286 description: Syntax error - Original JSON-text:{“Vaadin-Security-Key”:“0e46aec8-10f8-4c23-bb60-480549e54965”,“changes”:

and also there is a warning messane in the log:
Warning: Ignoring variable change for non-existent component, VAR_PID=PID153

Does anyone know the reason and how to handle it?


If I didn’t fresh the browser, I would receive a message and a log after a long long time:
Communication problem
Take note of any unsaved data, and click here to continue.
Invalid security key received

Log (no output of exception stack):
2010-12-4 13:10:16 org.apache.catalina.core.ApplicationContext log
Message: MySampleApp Application: Invalid security key received from

BTW, I am sure my widget is compilated as the same vaadin version as the application (a possible reason may caused Invalid security key), and MySampleApp can run successfully in most cases,

Any idea about the problem?

Hope someone could provide suggestions for me. The problem is being blocked my deployment.

Do you have any way to reproduce this? Ideally with a publicly available application such as

An invalid security key exception is thrown when either there is no security key stored in the session or the key sent by the client does not match the one in the session. Either one should not happen very often (if at all in normal usage).

EDIT: Does this happen only in IE?

The issue happens in my deployment environment (RedHat + Tomcat), but ok in my development environment (Win7 + Eclipse + Tomcat). If possible, please have a look at message
, I have no idea whether it’s associated to “Read timed out” or not.

Might I know whether “Invalid security key” can be caused by the expired session? because I didn’t refresh browser manually.

I will do the test with FF and feedback the result soon.
EDIT: During my 1+ hour, this happens in IE 6 & 8, and the latest FireFox 3.6.12 is ok.

I have recently encountered this “Invalid security key” error.

The client either closed Firefox 3.6.13 (or toggle between) , open another session Chrome 9.0. I believe the client just clicks on any data in nested Tab in Chrome that was inactive for a while (but before session timed out).

The log " applicationServlet: Invalid security key received from"

As u indicated there is session discrepancy between Chrome, and Firefox, and doesn’t happen often…but I am perflexed as to how to prevent this…or if there is any workaround/fix.

how to avoid this problem?

I’m facing the similar issue. Can you please help me out?

I’m using vaadin in my application and we used to generate reports using our application. If the report takes more than 30 mins, the GUI is throwing ‘Communication Problem ake note of any unsaved data, and click here to continue.’

I changed the time-out to 60 mins in web.xml but still it didn’t help me
Is there any session configuration specific to vaadin server? If yes, how can i override or change the time-out to 60 mins?

I’m completely blocked at this issue. Can anyone help me please?

Would anybody have more information on this issue?
Some of our customers seem to experience something that looks related. However I am unable to reproduce in our development environment.

Communication Error (SyntaxError): Syntax error description: Syntax error number: -214682786 - Original JSON-text: Browser: IE11

We also have a lot of log messages stating:

Warning: Ignoring variable change for non-existent component, VAR_PID=PID153 I think this last warning is caused by background threads performing updates on layouts that are already detached which we will resolve whilest upgrading to Vaadin 7.
We are however not sure if both problems relate to each other.

In my understanding, this issue occurs if vaadin server process a request more than 30 mins it throws ‘Communication Problem’, I found the solution by using client polling and add-ons, if you have any ideas please share with us, thanks

Please Help ! I have same error and could not solve it.
I’m using :

  • Vaadin 7.2

I see a tomcat log :

10 oct. 2014 15:13:11 com.vaadin.server.DefaultErrorHandler doDefault
ClientAbortException: Software caused connection abort: socket write error
 at org.apache.catalina.connector.OutputBuffer.doFlush(
 at org.apache.catalina.connector.OutputBuffer.flush(
 at org.apache.catalina.connector.CoyoteOutputStream.flush(
 at sun.nio.cs.StreamEncoder.implFlush(Unknown Source)
 at sun.nio.cs.StreamEncoder.flush(Unknown Source)
 at Source)
 at com.vaadin.server.communication.UIInitHandler.commitJsonResponse(
 at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(
 at com.vaadin.server.SynchronizedRequestHandler.handleRequest(
 at com.vaadin.server.VaadinService.handleRequest(
 at com.vaadin.server.VaadinServlet.service(
 at javax.servlet.http.HttpServlet.service(
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(
 at org.apache.catalina.core.StandardWrapperValve.invoke(
 at org.apache.catalina.core.StandardContextValve.invoke(
 at org.apache.catalina.core.StandardHostValve.invoke(
 at org.apache.catalina.valves.ErrorReportValve.invoke(
 at org.apache.catalina.core.StandardEngineValve.invoke(
 at org.apache.catalina.connector.CoyoteAdapter.service(
 at org.apache.coyote.http11.Http11Processor.process(
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(
 at Source)
Caused by: Software caused connection abort: socket write error
 at Method)
 at Source)
 at Source)
 at org.apache.coyote.http11.InternalOutputBuffer.realWriteBytes(
 at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(
 at org.apache.coyote.http11.InternalOutputBuffer.flush(
 at org.apache.coyote.http11.Http11Processor.action(
 at org.apache.coyote.Response.action(
 at org.apache.catalina.connector.OutputBuffer.doFlush(
 ... 23 more