Why event mouse click opens in new tab? scriptcase 9.12,

Scriptcase 9 General
#1

when i click on any left menu item in development environment , it opens in new tab. i want it to open in same tab.
for example, if i click on on validate event, the right menu should show the window of on validate, but instead, a completely new tab opens.

any idea how to not open in new tab?

#2

something wrong with your DEV. i have a fresh install and everything works as usual.