Break block but block goes back!

[Lninja]

the bugs is
when i place block it returned to inventory

some times item disappeared

and when i break a block it returned to its place and some times i get suffocated

How to fix that please?

 

[Sleepybear]

Check your permissions and plugins.

Also if you have spawn-protection set in your server.properties file it will stop block breaking/placement for that radius from the spawn point.