Endless redirect in widgets.php >:(

Hey,
I have a extrem annoying error! First I had the bug that I got into an endless redirect (Firefox) or an empty page (Chrome and IE) when i accessed the wp-admin (dashboard. I was able to fix this after months of research and deleting and reinstalling wordpress approximately a thousand times. Since this error is occuring in various older versions too I ask myself why its still in Version 3.4.2! But however now I got a more annoying bug! When I try to add a widget to any sidebar I have an endless redirect like with the wp-admin bug. Nothing helps. I even read the hole article at the ticket system which was very annoying and difficult because I am no PHP professional. But who cares? I edited the file as described in the ticket but it still doesnt work! Whats wrong with WordPress??? Why do I get these ultra annoying errors after months of using WordPress?! And why isnt Auttomatic able to fix these damned bugs over lots of versions?!

Please help me! I dont know what to do! I love WordPress as a CMS but these errors are crushing my brain!

Sad regards, Valentin from Germany