Arduino Due doesnt start with new IDE

Hello,

I m new in this forum. I m running an Arduino Due with 5" TFT (all from Saint Smart) and UTFT Library. Its was easely to prgramm with IDE 1.5.6 but after update to 1.6.5 there is no reaction from board. Only the backlight of TFT is on. I dont have any idea.
I m using AruinoISP programer.

Regards Kristian

You've downloaded the Due extension module? Arduino 1.6 has downloadable modules
for the more exotic devices to keep the main download smaller.

Handy tip: Never overwrite a piece of software with an old version, install the new version
elsewhere and test it out - you then have the option of using either.

I am also having problems (OS X 10.10.3, Arduino 1.6.5). I downloaded the extension module, the Board Manager says that version 1.6.4 is installed, but the Due does not show in the list of boards.

Hi MarkT,
you are talking about board manager in tools - boards? There the due board extension is installed. uninstalled and newly installed - no change.