Pycharm completely freezes sometimes when autopopup code completion appears

I work on Pycharm 2017.2 under the Arch linux distribution. My problem is that, from time to time, IDE freezes when an autocomplete popup appears. Nevertheless, it happens randomly with no obvious pattern, at least to me; in most cases, the autocomplete works as it is supposed to. During the freeze of the app happens, the popup is a blank grey box with no visible words inside it. Therefore, the only solution is to kill it and restart again. I could not find anything useful on the web related to this subject. I tried to go back to openjdk7 instead of 8 that i currently use but it did not solve the problem. I uploaded the automatic thread dumps through the web form as "pycharm_crash.zip".