Used device manager once, now I can't set security to 'none' Phone is an LG Nexus.

I was messing around with security settings and decided to try using a pattern to unlock my phone. No more than 5 minutes later, I completely forget the pattern I set. Did some googling and used Android Device Manager on my PC to remotely set a password on the phone. Successfully regained access to my phone.

I prefer to have no security on my phone specifically to avoid situations like this. My problem now is when I go to security settings, the "None" option is greyed out and says "Disabled by administrator, encryption policy, or credential storage." So I selected Device Administrators and un-checked "android device manager."

But I still cannot select "None." Encryption is not enabled. I'm tempted to select "clear credentials," but there's a big list of default credentials and I'm afraid removing them might be bad. Is there a specific credential I should disable?

TL;DR: Can't set screen lock to NONE. Android Device Manager is disabled. Not sure if I should clear all credentials.
Ok, just posting an answer in case someone with the same problem finds this.

I took a change and hit "clear credentials." Afterwards I was able to select NONE for screen-lock again. So far haven't noticed and side-effects to clearing credentials.