I was just using LR 4.3 (trial) to edit some photos in a collection I exported previously, but now when I use the Clone or Heal brush - the selection and sample circles are missing and not shown. As soon as I click on the spot to clone/heal out, it is immediately changed and I cannot tell where the sample is taken from. If I move my cursor to the area again, it changes to the double-pointing arrow to resize the edit circle and I can adjust it but the edges of the circle are not shown - only the area of pixels change. There is no difference if I left click or tap the touchpad on my laptop to apply the clone/heal.
I had installed the Nik Software package 1.0.0.7 in the mean time, and considering that may be the cause - uninstalled it and rebooted. The issue remained. I uninstalled LR 4.3 and rebooted, installed LR 4.4 and tested again - still the issue remains. I am not sure what else to test. Running on fresh Win 7 install (64bit) on ASUS UX32VD laptop.
ref: http://help.adobe.com/en_US/lightroom/using/WS43660fa5a9ec95a81172e081 210db09b94-7ffa.html
http://www.niksoftware.com/nikcollection/usa/index.php