Collaborate package throws errors when updated to latest version 1.2.9 or 1.2.7 through package manager

Steps to reproduce:
1) Create new project
2) Window > Package Manager
3) Update Collab to version 1.2.7 or 1.2.9.

Actual result: Namespace error appear in the console.

Occurs on Collab package version : 1.2.9, 1.2.7

Working fine on Collab package version: 1.2.6

Verified on : 2018.3.0a9, 2018.3.0a7.

Environment: Both Windows and Mac

Stack trace:
1)
Library\PackageCache\com.unity.collab-proxy@1.2.9\Editor\Collab\CollabToolbarButton.cs(9,42): error CS0246: The type or namespace name 'SubToolbar' could not be found (are you missing a using directive or an assembly reference?)
2)
Library\PackageCache\com.unity.collab-proxy@1.2.9\Editor\Collab\CollabToolbarButton.cs(98,30): error CS0115: 'CollabToolbarButton.OnGUI(Rect)': no suitable method found to override