Solved crashes without reason

how can i protect my plugin to crashes like hasPermission() on null or setComponents() on null or getName() on null in all of this crashes is not line or something only line in pocketmine source.
e.g.

Code:

PocketMine-MP Crash Dump Sun Jul 26 18:56:04 UTC 2015

Error: Call to a member function getName() on null
File: /src/pocketmine/level/Level__64bit
Line: 2634
Type: E_ERROR

Code:
[2625]         return (int) $this->time;
[2626]     }
[2627] 
[2628]     /**
[2629]     * Returns the Level name
[2630]     *
[2631]     * @return string
[2632]     */
[2633]     public function getName(){
[2634]         return $this->provider->getName();
[2635]     }
[2636] 
[2637]     /**
[2638]     * Returns the Level folder name
[2639]     *
[2640]     * @return string
[2641]     */
[2642]     public function getFolderName(){
[2643]         return $this->folderName;
[2644]     }

Backtrace:
#0 (): pocketmine\Server->crashDump()

PocketMine-MP version: 1.5dev #1255 [Protocol 27; API 1.12.0]
Git commit: 0000000000000000000000000000000000000000
uname -a: Linux sith 3.19.0 #2 SMP Sat Jul 18 18:32:05 CEST 2015 x86_64
PHP Version: 5.6.4
Zend version: 2.6.0
OS : Linux, linux

Loaded plugins:
FastTransfer 1.0.2 by shoghicp for API(s) 1.12.0
AllServers 1.1 by hoyinm for API(s) 1.12.0
SimpleAuth 1.7.1 by PocketMine Team, shoghicp for API(s) 1.12.0
BedWars 1 by CreeperFace for API(s) 1.12.0

new install pocketmine

to pocketmine build 1244 it work

Don't call any functions on the Player after he has left the server or before he has spawned.

and when this happens?

Spoiler

PocketMine-MP Crash Dump Mon Jul 27 08:19:04 UTC 2015

Error: Call to a member function setComponents() on null
File: /src/pocketmine/entity/Entity__64bit
Line: 1427
Type: E_ERROR

Code:
[1418] $from = Position::fromObject($this, $this->level);
[1419] $to = Position::fromObject($pos, $pos instanceof Position ? $pos->getLevel() : $this->level);
[1420] $this->server->getPluginManager()->callEvent($ev = new EntityTeleportEvent($this, $from, $to));
[1421] if($ev->isCancelled()){
[1422] return \false;
[1423] }
[1424] $this->ySize = 0;
[1425] $pos = $ev->getTo();
[1426]
[1427] $this->setMotion($this->temporalVector->setComponents(0, 0, 0));
[1428] if($this->setPositionAndRotation($pos, $yaw === \null ? $this->yaw : $yaw, $pitch === \null ? $this->pitch : $pitch) !== \false){
[1429] $this->resetFallDistance();
[1430] $this->onGround = \true;
[1431]
[1432] $this->lastX = $this->x;
[1433] $this->lastY = $this->y;
[1434] $this->lastZ = $this->z;
[1435]
[1436] $this->lastYaw = $this->yaw;
[1437] $this->lastPitch = $this->pitch;

Backtrace:
#0 (): pocketmine\Server->crashDump()

PocketMine-MP version: 1.5dev #1255 [Protocol 27; API 1.12.0]
Git commit: 0000000000000000000000000000000000000000
uname -a: Linux sith 3.19.0 #2 SMP Sat Jul 18 18:32:05 CEST 2015 x86_64
PHP Version: 5.6.4
Zend version: 2.6.0
OS : Linux, linux

Loaded plugins:
FastTransfer 1.0.2 by shoghicp for API(s) 1.12.0
AllServers 1.1 by hoyinm for API(s) 1.12.0
SimpleAuth 1.7.1 by PocketMine Team, shoghicp for API(s) 1.12.0
BedWars 1 by CreeperFace for API(s) 1.12.0

i only stay on one place without move and after few minutes server crashes with error setComponents() on null so please how can i repair it?

or server crashes after start -,-

im wondering.... i dont see this by my server... get never this bug... but dont use any official plugins...only my own...

Me too it is by my new bedwars

get u this problem if u disable simple auth?

Hm i didnt try it but i have problem with PVP too is it simple auth bug?
And on my local server i didnt see only any bug

can be... dont know really... can only speculate