# Error on startup for mediacache using Amazon S3

**URL:** https://community.wowza.com/t/error-on-startup-for-mediacache-using-amazon-s3/43869
**Category:** Wowza Streaming Engine
**Created:** [September 11, 2014, 2:31pm UTC](https://community.wowza.com/t/error-on-startup-for-mediacache-using-amazon-s3/43869 "2014-09-11T14:31:17Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Gary\_Monk](https://avatars.discourse-cdn.com/v4/letter/g/898d66/32.png) [@Gary\_Monk](https://community.wowza.com/u/Gary_Monk)
#### Post date: [September 11, 2014, 2:31pm UTC](https://community.wowza.com/t/error-on-startup-for-mediacache-using-amazon-s3/43869/1 "2014-09-11T14:31:17Z")

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I’m receiving the following error when the mediacache gets initialized…

ERROR server comment 2014-09-11 15:19:22 - - - - - 0.269 - - - - - - - - ServerUtils.loadServerListener: Error creating (com.wowza.wms.plugin.mediacache.impl.MediaCacheServerListener) : java.lang.ClassNotFoundException: com.wowza.wms.plugin.mediacache.impl.MediaCacheServerListener|at java.net.URLClassLoader$1.run(URLClassLoader.java:372)|at java.net.URLClassLoader$1.run(URLClassLoader.java:361)|at java.security.AccessController.doPrivileged(Native Method)|at java.net.URLClassLoader.findClass(URLClassLoader.java:360)|at java.lang.ClassLoader.loadClass(ClassLoader.java:424)|

From what I can tell the listener is setup properly based on the article “How to use Amazon S3 with a standalone Wowza Media Server and the MediaCache AddOn”

Thanks

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### 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: [September 12, 2014, 7:18am UTC](https://community.wowza.com/t/error-on-startup-for-mediacache-using-amazon-s3/43869/2 "2014-09-12T07:18:02Z")

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Hi Gary, can you please tell us what version of Wowza you are running?

As of Wowza 4.x MediaCache is no longer a plug in, it is built into Wowza, so **com.wowza.wms.plugin.mediacache.impl.MediaCacheServerListener** is an invalid reference in 4.x

The correct reference would be **com.wowza.wms.mediacache.impl.MediaCacheServerListener**

This guide will show you how to configure Media Cache with the new Wowza Streaming Engine:

[How to scale video on demand streaming with Media Cache](https://www.wowza.com/docs/how-to-scale-video-on-demand-streaming-with-media-cache)

I hope this helps.

Salvadore