https://imgur.com/tybIuE6

Hi
I just upgraded my cpu ,memory,and motherboard from 4770k 8gb to 9900k 32gb,all other hardware are unchanged,my GPU is r9 290,tablet is intuos pro M.
I did a clean Windows10 install,downloaded krita from steam,and got this weird problem,there are random transparent squares in brush stroke,as in the image above,and the brush blinkes squares in movement, krita often freezes after a while(not crash,there are no record in kritacrash.log).I've been using krita for 3 months,this never happened.
I've tried:
reinstall different versions of graphic driver; switch to Intel integrated graphic card; reinstall tablet driver
mess around with settings like canvas graphic acceleration ,internal pool. or reset krita settings,reinstall krita
nothing makes any difference,all my other software work fine,including Photoshop.
Please help,any idea what causes this

Have you used a memory checker? It sounds to me like your new memory or the slots might be damaged.

boudewijn wrote:Have you used a memory checker? It sounds to me like your new memory or the slots might be damaged.

thanks for the reply
it does sound like a memory problem,i just ran two hours of aida64 stress memory,memtest and windows 10 memory diagnose,no error though.
I noticed that when cpu and memory are at 100% usage,brush strokes in krita still blink square shapes,but don't leave square on canvas

boudewijn wrote:Have you used a memory checker? It sounds to me like your new memory or the slots might be damaged.

just downloaded Krita 4.2,it's fixed! no random squares,and it's much quicker on tasks like press delete to clear layer,don't kown why my Krita 4.1.7 is broken,the two share the same setting.
love the new move selection and flow, thanks the team.please,is there a estimated release date

Weird... Keep in mind that 4.2 is unstable: there is a bug in the core that will cause crashes when working with larger images. We want to release in May.