installing deb package

I'm unable to install Vivaldi browser deb package to newest 16.04 ChaletOS. When I click 'install' button label changes to 'installing' for a 2 seconds and that's all , no message, nothing. On the other hand the same installation package works well on previous 14.04 OS version.

the same apply to other deb packages

I ran into this problem and if I recall it's tied to this new Ubuntu install program (which I dislike and it has a connection to Gnome).  I managed to install Vivaldi just fine with the Gdebi software.  So first of all make sure you've updated your ChaletOS (go into terminal then type 'sudo apt-get update') once you've updated then utilize your file manager and located the Vivaldi deb package. Now right click on the .deb file and choose 'open with' then 'application installer'.  Personally I stay clear of that new installer and instead I stick with Synaptic/Terminal and Gdebi.

yes, it's Ubuntu 16.04 Install program problem, I managed to do it with Terminal

I have same problem. You can also right click and select "open with" then select "application installer" (gdebi) or "application center" (software manager).

hope this helps!