Someone help. Players cant build place or destroy objects. They just reappear dissapear

hi guys. when new players and try to build destroy blocks they just reappear/dissapear
heres my permissions
groups:
default:
permissions:
- modifyworld.*
Owner:
permissions:
- '*.*'
prefix: '&6O&5W&1N&eE&4R&f><'
Admin:
permissions:
- '*.*'
prefix: '&6A&5D&6M&5I&6N&f><'
C-Prisoner:
prefix: '&1C-Prisoner&f><'
permissions:
- modifyworld.*
default: true
B-Prisoner:
permissions:
- modifyworld.*
prefix: '&4B-Prisoner&f><'
A-Prisoner:
permissions:
- modifyworld.*
prefix: '&5A-Prisoner&f><'
Elite-Prisoner:
permissions:
- modifyworld.*
prefix: '&6Elite-Prisoner&f><'
Free:
permissions:
- modifyworld.*
prefix: '&1F&2R&4E&1E&f><'

btw i only have Pex Auto saver modifyworld chat manager as i deleted all other plugins to try and fix it.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Download PermissionsEx, it's a lot better and easier.. After around 20 server as an Admin i suggest that is the best.

 

Then post the permissions in PEX

 

thanks guys but friend showed me what to do