# Internal BufferUnderflowException **URL:** \ **Category:** Wowza Streaming Engine\ **Created:** [October 9, 2014, 11:46am UTC](https://community.wowza.com/t/internal-bufferunderflowexception/41230 "2014-10-09T11:46:43Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Y\_T](https://avatars.discourse-cdn.com/v4/letter/y/9f8e36/32.png) [@Y\_T](https://community.wowza.com/u/Y_T)\ **Post date:** [October 9, 2014, 11:46am UTC](https://community.wowza.com/t/internal-bufferunderflowexception/41230/1 "2014-10-09T11:46:43Z")
I’m using Wowza Streaming Engine 4.0.6 build 12199 And noticed that sometimes (0-10 times per hour) following error occurs (logged using log4j): 09 Oct 2014 00:22:25,309 25713053 [ServerHandler.64] ERROR _definst_ - constructor AMFDataObj(ByteBuffer)[6:27] : java.nio.BufferUnderflowException|at java.nio.HeapByteBuffer.get(HeapByteBuffer.java:145)|at java.nio.ByteBuffer.get(ByteBuffer.java:694)|at com.wowza.wms.amf.AMFDataItem.deserialize(AMFDataItem.java:473)|at com.wowza.wms.amf.AMFDataItem.(AMFDataItem.java:176)|at com.wowza.wms.amf.AMFData.deserializeInnerObject(AMFData.java:340)| 09 Oct 2014 00:22:25,309 25713053 [ServerHandler.64] ERROR _definst_ - processNextRequest: error : java.lang.NullPointerException| 09 Oct 2014 00:22:25,369 25713113 [ServerHandler.64] ERROR _definst_ - constructor AMFDataObj(ByteBuffer)[6:27] : java.nio.BufferUnderflowException|at java.nio.HeapByteBuffer.get(HeapByteBuffer.java:145)|at java.nio.ByteBuffer.get(ByteBuffer.java:694)|at com.wowza.wms.amf.AMFDataItem.deserialize(AMFDataItem.java:473)|at com.wowza.wms.amf.AMFDataItem.(AMFDataItem.java:176)|at com.wowza.wms.amf.AMFData.deserializeInnerObject(AMFData.java:340)| They are always occur simultaneously, 3 errors one after another like listed above. Errors doesn’t show app they occurred in, just “ERROR _definst_”. Have no idea what is it and what i can do with it. Please advise. ---
**Author:** ![Matt\_Young](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/matt_young/32/389_2.png) [@Matt\_Young](https://community.wowza.com/u/Matt_Young)\ **Post date:** [October 9, 2014, 7:00am UTC](https://community.wowza.com/t/internal-bufferunderflowexception/41230/2 "2014-10-09T07:00:34Z")
Are you experiencing any issues with your streams when you see this error? The BufferUnderflowException can happen for a variety of reasons but many times its due to bandwidth being insufficient or not enough data etc. ---
**Author:** ![Y\_T](https://avatars.discourse-cdn.com/v4/letter/y/9f8e36/32.png) [@Y\_T](https://community.wowza.com/u/Y_T)\ **Post date:** [October 10, 2014, 2:06pm UTC](https://community.wowza.com/t/internal-bufferunderflowexception/41230/3 "2014-10-10T14:06:56Z")
> Are you experiencing any issues with your streams when you see this error? The BufferUnderflowException can happen for a variety of reasons but many times its due to bandwidth being insufficient or not enough data etc. There are no streams on this server. It is used for messaging flash clients. Do you mean client’s bandwidth?