I have previously discussed machine state and 4 Way Authentication briefly, here I want to discuss Open System Authentication specifically 802.11 Association. Before an RSNA is established between two devices they have to first go through Open System Authentication. STA must be Associated and Authenticated to the device.
As shown in the picture below following events happen when a client starts the connection process in Open System Authentication:
Finally the station is associated and Open System Authentication is complete. If there is an issue with any capabilities not matching then this association would not complete. Quick example would be clients that only support WPA/TKIP but the access point parameters are WPA2/AES. In this case RSN IE capabilities will not match and the Association will not complete successfully.