Why is my unity5.3.3(in mac os) has no 'tools' menu on the top bar?

Hi there.
I want to use ProBuilder(an extension for Unity).

It is said:

In order to create or edit with ProBuilder, you will need the GUI Panel open. This is done by selecting from the top menu bar in Unity:

Tools > ProBuilder > Open Probuilder Window

This will open the ProBuilder window. By default the window is opened as a dockable panel, but may be changed to a floating window by context-clicking (Control-Click on Mac, Right-Click on Windows) and selecting one of the floating options.

But the thing is, I found that my unity has no “tools” menu for me to select.
2628963--184769--upload_2016-5-10_14-54-41.png
Do you know how I can fix this problem and use ProBuilder?

Thanks a lot!

It looks like something changed and the probuilder version for 5.3.0 is not working in 5.3.3.
You could try to contact the author of the asset or wait for a update that may fix the issue.
Maybe you could post in the probuilder forum about this problem, there you probably get a faster / more direct answer from probuilder author / creator.
http://www.protoolsforunity3d.com/forum/