It's a problem (probably bug?) in the OpenJDK Java 9 Runtime Environment which is used by PyCharm.
Java 9 is still in its development phase and can't be expected to be stable until around March 2017.
You should remove Java 9 and install and use Java 8 instead.
sudo apt install openjdk-8-jre
sudo apt purge openjdk-9-*
But before you confirm the second command (purge Java 9), please check the shown list of packages that will be removed. If anything you installed depends directly on Java 9, it will get removed as well. Cancel and report back if something is listed there that you want to keep or are unsure about.