# Problem starting Wowza Meida Engine 4 with custom module

**URL:** <https://community.wowza.com/t/problem-starting-wowza-meida-engine-4-with-custom-module/39447>\
**Category:** Wowza Developer Dojo\
**Tags:** wowza-streaming-server-java-api\
**Created:** [March 28, 2014, 8:53pm UTC](https://community.wowza.com/t/problem-starting-wowza-meida-engine-4-with-custom-module/39447 "2014-03-28T20:53:23Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Arash\_Mosharraf](https://avatars.discourse-cdn.com/v4/letter/a/edb3f5/32.png) [@Arash\_Mosharraf](https://community.wowza.com/u/Arash_Mosharraf)\
**Post date:** [March 28, 2014, 8:53pm UTC](https://community.wowza.com/t/problem-starting-wowza-meida-engine-4-with-custom-module/39447/1 "2014-03-28T20:53:23Z")

</div>

I am trying to debug my custom Wowza module that is written by others in eclipse (Windows 8) but I get the following error and cannot figure out what class it’s referring too. I already enabled debug logging but wowza give me the error even before it gets to my OnAppStart break point of my . I would really appreciate if someone could point me to where I can find more info on this. Also, this module was written for earlier version of Wowza and I looked the methods and properties that have changed in Wowza 4 but I think it should boot up to my app first at least before producing the error.

```auto
Error starting: java.lang.reflect.InvocationTargetException
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at com.wowza.wms.bootstrap.Bootstrap.startServer(Bootstrap.java:555)
	at com.wowza.wms.bootstrap.Bootstrap.main(Bootstrap.java:67)
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/lang/SystemUtils
	at com.wowza.wms.bootstrap.BootstrapSystemTuningInfo.getSystemTuningInfo(BootstrapSystemTuningInfo.java:81)
	at com.wowza.wms.server.ServerTuningHandler.<init>(ServerTuningHandler.java:248)
	at com.wowza.wms.server.Server.<init>(Server.java:862)
	at com.wowza.wms.server.Server.getInstance(Server.java:907)
	at com.wowza.wms.server.Server.start(Server.java:956)
	... 6 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.lang.SystemUtils
	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 11 more

```

---

<div class="post-metadata">

**Author:** ![sal\_jefferson](https://avatars.discourse-cdn.com/v4/letter/s/6de8d8/32.png) [@sal\_jefferson](https://community.wowza.com/u/sal_jefferson)\
**Post date:** [March 29, 2014, 5:35am UTC](https://community.wowza.com/t/problem-starting-wowza-meida-engine-4-with-custom-module/39447/2 "2014-03-29T05:35:27Z")

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Hi there.

To fix this error. In Eclipse, right click on the project in the left menu and choose “properties”

Next, click on the Run/Debug settings on the left, highlight the launch configuration and click Edit

Under the “arguments” tab, add the following line to the output in “VM Arguments”

On Windows:

```auto
-Dcom.wowza.wms.native.base="win"

```

On Mac:

```auto
-Dcom.wowza.wms.native.base="osx"

```

Salvadore

---

<div class="post-metadata">

**Author:** ![Arash\_Mosharraf](https://avatars.discourse-cdn.com/v4/letter/a/edb3f5/32.png) [@Arash\_Mosharraf](https://community.wowza.com/u/Arash_Mosharraf)\
**Post date:** [March 29, 2014, 7:42am UTC](https://community.wowza.com/t/problem-starting-wowza-meida-engine-4-with-custom-module/39447/3 "2014-03-29T07:42:17Z")

</div>

> Hi there.
> 
> To fix this error. In Eclipse, right click on the project in the left menu and choose “properties”
> 
> Next, click on the Run/Debug settings on the left, highlight the launch configuration and click Edit
> 
> Under the “arguments” tab, add the following line to the output in “VM Arguments”
> 
> On Windows:
> 
> ```auto
> -Dcom.wowza.wms.native.base="win"
> 
> ```
> 
> On Mac:
> 
> ```auto
> -Dcom.wowza.wms.native.base="osx"
> 
> ```
> 
> Salvadore

Thanks Salvador,

It actually started working with no apparent errors? What does the line above do in general? I tried to look it up but couldn’t find that much documentation for it. It appears that you need to have that setup in your IDE anyways.