If you get this error please check if you have the FACEIT (https://www.faceit.com/) client installed. If you do, turn it off and try again. The game should now start as normal.
If that does not help, you may need to uninstall the app completely.
We are investigating this issue and hope to somehow fix the compatibility issue that seems to exist.
NOTE: In the past this error has also been found to be triggered by anti-virus apps including Kaspersky, ESET and Avast! , although those reports are rare now.