How do I change my lock screen back to a slide screen

[Jacob]

My phone wont let me change my pattern lock back to a regular slide lock, it keeps saying disable by administrator, encryption policy or credential storage
How do I change it back and what does that mean

 

[B. Diddy]

Welcome to Android Central! Which phone? Is it encrypted? Encrypted phones require password or PIN.

If it isn't encrypted, go to Settings>Security>Clear Credentials. Now try again.