Custom widget of ChatTranscript giving error in Stage. (Working fine in Dev env!!!)

Summary

I am extending ChatTranscript Widget. It is working fine on dev env. However when I stage it gives error

Content

I am extending ChatTranscript Widget. It is working fine on dev env. However when I stage it gives error :

<b>Fatal error</b>: Class 'RightNow\Widgets\ChatTranscript' not found in <b>/cgi-bin/tomtom_de.cfg/scripts/cp/generated/staging/staging_01/optimized/widgets/custom/chat/CustomChatTranscript/1.0/optimized/optimizedWidget.php</b> on line <b>1</b><br />

 

Can some one help me out. It is very strange behavior , everything working perfect on dev env.

Version

3.7

Code Snippet

error on line :
class CustomChatTranscript extends \RightNow\Widgets\ChatTranscript