players are invincible with no with armour on and here is no particles

Few questions here:

• Is this a pure vanilla server, modded or something like spigot/bukkit.

• Do you have a screenshot/more info?

hello sorry for no getting back I had a power outage and I didn't know how to respond on my phone and i have found the problem was with optfine 

If it was with optifine then the issue should really get removed by somebody v-v

As mentioned above, optifine is not supported.