ofxAudioUnit - Error compiling - Poco::FastMutex

I have downloaded ofxAudioUnit and move it to the addson directory.

When I try to run the examples I have this error:

file: ofxAudioUnitDSPNode.cpp
line 284: if(ctx->bufferMutex.try_lock()) {
error: No member named 'try_lock' in 'Poco::FastMutex'

Can you point me in the proper direction to solve this problem?

Thanks