# Webpage example "error stopping module"

**URL:** <https://forum.inductiveautomation.com/t/webpage-example-error-stopping-module/26798>\
**Category:** Module Development\
**Created:** [July 23, 2019, 1:31pm UTC](https://forum.inductiveautomation.com/t/webpage-example-error-stopping-module/26798 "2019-07-23T13:31:59Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Rhys\_m](https://avatars.discourse-cdn.com/v4/letter/r/13edae/32.png) [@Rhys\_m](https://forum.inductiveautomation.com/u/Rhys_m)\
**Post date:** [July 23, 2019, 1:31pm UTC](https://forum.inductiveautomation.com/t/webpage-example-error-stopping-module/26798/1 "2019-07-23T13:31:59Z")

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Hi,

I am creating a module that will have webpage configuration, so have been building one based off of the example on git. However, when I upgrade the module I am getting the error of “error stopping module” looking through the logs, it seems to begin here in the code

`at com.inductiveautomation.ignition.examples.hce.GatewayHook.shutdown(GatewayHook.java:201)`

ultimately throwing this exception

`java.lang.IllegalArgumentException: Argument 'requestCycle' may not be null.`

I have tested by building the example webpage module and get the same results.

Any ideas?

heres the entire trace for reference

```auto
java.lang.IllegalArgumentException: Argument 'requestCycle' may not be null.

at org.apache.wicket.util.lang.Args.notNull(Args.java:41)

at org.apache.wicket.Application.fetchCreateAndSetSession(Application.java:1552)

at org.apache.wicket.Session.get(Session.java:152)

at org.apache.wicket.RestartResponseAtInterceptPageException$InterceptData.get(RestartResponseAtInterceptPageException.java:146)

at org.apache.wicket.RestartResponseAtInterceptPageException$1.matchedData(RestartResponseAtInterceptPageException.java:211)

at org.apache.wicket.RestartResponseAtInterceptPageException$1.getCompatibilityScore(RestartResponseAtInterceptPageException.java:179)

at org.apache.wicket.request.mapper.CompoundRequestMapper.mapRequest(CompoundRequestMapper.java:134)

at org.apache.wicket.protocol.https.HttpsMapper.mapRequest(HttpsMapper.java:92)

at org.apache.wicket.request.mapper.CompoundRequestMapper.unmount(CompoundRequestMapper.java:209)

at org.apache.wicket.protocol.http.WebApplication.unmount(WebApplication.java:387)

at com.inductiveautomation.ignition.examples.hce.GatewayHook.shutdown(GatewayHook.java:201)

at com.inductiveautomation.ignition.gateway.modules.ModuleManagerImpl$LoadedModule.shutdown(ModuleManagerImpl.java:2525)

at com.inductiveautomation.ignition.gateway.modules.ModuleManagerImpl$3.call(ModuleManagerImpl.java:784)

at com.inductiveautomation.ignition.gateway.modules.ModuleManagerImpl.executeModuleOperation(ModuleManagerImpl.java:905)

at com.inductiveautomation.ignition.gateway.modules.ModuleManagerImpl.uninstallModuleInternal(ModuleManagerImpl.java:776)

at com.inductiveautomation.ignition.gateway.modules.ModuleManagerImpl$UninstallCommand.execute(ModuleManagerImpl.java:1828)

at com.inductiveautomation.ignition.gateway.modules.ModuleManagerImpl$Receiver.receiveCall(ModuleManagerImpl.java:1801)

at com.inductiveautomation.ignition.gateway.redundancy.QueueableMessageReceiver.receiveCall(QueueableMessageReceiver.java:47)

at com.inductiveautomation.ignition.gateway.redundancy.RedundancyManagerImpl.dispatchMessage(RedundancyManagerImpl.java:813)

at com.inductiveautomation.ignition.gateway.redundancy.RedundancyManagerImpl$ExecuteTask.run(RedundancyManagerImpl.java:849)

at com.inductiveautomation.ignition.common.execution.impl.BasicExecutionEngine$ThrowableCatchingRunnable.run(BasicExecutionEngine.java:518)

at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)

at java.base/java.util.concurrent.FutureTask.run(Unknown Source)

at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at java.base/java.lang.Thread.run(Unknown Source)

```

any pointers would be appreciated, all I have found so far online seems to point to threads not finishing in time 🤷‍♂️

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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:** [July 23, 2019, 2:07pm UTC](https://forum.inductiveautomation.com/t/webpage-example-error-stopping-module/26798/2 "2019-07-23T14:07:42Z")

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I’m not sure why that example is calling unmount at all, I’m gonna ask around and see if it needs updating or something.

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<div class="post-metadata">

**Author:** ![Rhys\_m](https://avatars.discourse-cdn.com/v4/letter/r/13edae/32.png) [@Rhys\_m](https://forum.inductiveautomation.com/u/Rhys_m)\
**Post date:** [July 23, 2019, 2:35pm UTC](https://forum.inductiveautomation.com/t/webpage-example-error-stopping-module/26798/3 "2019-07-23T14:35:33Z")

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@Kevin.Herron thankyou, I’m not sure if its down the system failing to stop the module, or whether because its not unmounting, but if you make changes to any of the wickets then install the module over the top, the updates dont show unless you do a reboot, so it seems linked somehow.