I want to overwritte views/site/master.js do add a sidebar on the left.

[Andorxor]

Is there a upgrade friendly way to do it?

[yuri]

No. There's the ability to override navbar view. that will be available in 5.7 version.

[telecastg]

Just read this old posting, can you please provide a documentation or example reference ?. Thanks !

[espcrm]

Might have to yuri