Wireless toolbar options greyed out

I used airmon-ng to create a monitor interface on my wireless card, and airodump-ng to capture some packets. However, when I load the capture file into wireshark to decrypt it, I am not able to do so. have enabled wireless decryption in the preferences, and added wpa keys. However, the wireless toolbar options are all greyed out except for the button that switches between "wireshark" and none, and the decryption keys button is completely missing. I have tried toggling the "Assume Packets Have FCS" and the "Ignore the Protection bit" options, all to no avail. What am I doing wrong? Thanks.