Global Planning Error

Hi, when i'm linking to activities in global planning i'm getting an error

and the following activies are not in order

2018-11-14 09:46:16.856 ***** ERROR ***** [V7.2.7] ERROR *****
2018-11-14 09:46:16.856 ***** ERROR ***** [V7.2.7] on file '/var/www/html/model/ProjectMain.php' at line (647)
2018-11-14 09:46:16.856 ***** ERROR ***** [V7.2.7] cause = Creating default object from empty value



Any idea ?

ok,

NOTE : below explanation is only happenning when "Automatic run plan" is Checked

i'm selecting the arrow between to activities, i hit the red X to delete the link



it says in a green box, dependency link removed

the and i get this message

2018-11-14 09:46:16.856 ***** ERROR ***** [V7.2.7] ERROR *****
2018-11-14 09:46:16.856 ***** ERROR ***** [V7.2.7] on file '/var/www/html/model/ProjectMain.php' at line (647)
2018-11-14 09:46:16.856 ***** ERROR ***** [V7.2.7] cause = Creating default object from empty value.

i'm also getting these error message

2018-11-16 08:34:43.530 ***** ERROR ***** [V7.2.7] Exception-[42000] SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') or (successorRefType='' and successorRefId=)' at line 1
2018-11-16 08:34:43.530 ***** ERROR ***** [V7.2.7] For query : select count(*) as cpt from dependency where (predecessorRefType='' and predecessorRefId=) or (successorRefType='' and successorRefId=)
2018-11-16 08:34:43.530 ***** ERROR ***** [V7.2.7] Strack trace :
2018-11-16 08:34:43.530 ***** ERROR ***** [V7.2.7] #0 Sql->query called at [/var/www/html/model/persistence/SqlElement.php:2465]
2018-11-16 08:34:43.531 ***** ERROR ***** [V7.2.7] #1 SqlElement->countSqlElementsFromCriteria called at [/var/www/html/model/PlanningElementExtension.php:131]
2018-11-16 08:34:43.531 ***** ERROR ***** [V7.2.7] #2 PlanningElementExtension->checkDelete called at [/var/www/html/model/Dependency.php:250]
2018-11-16 08:34:43.531 ***** ERROR ***** [V7.2.7] #3 Dependency->delete called at [/var/www/html/tool/removeDependency.php:48]

2018-11-16 08:37:19.242 ***** ERROR ***** [V7.2.7] HACK ================================================================
2018-11-16 08:37:19.243 ***** ERROR ***** [V7.2.7] Try to hack detected
2018-11-16 08:37:19.243 ***** ERROR ***** [V7.2.7] Source Code = Id 'undefined' is not numeric
2018-11-16 08:37:19.243 ***** ERROR ***** [V7.2.7] QUERY_STRING = id=undefined
2018-11-16 08:37:19.243 ***** ERROR ***** [V7.2.7] REMOTE_ADDR = 10.1.120.140
2018-11-16 08:37:19.243 ***** ERROR ***** [V7.2.7] SCRIPT_FILENAME = /var/www/html/tool/dynamicDialogDependency.php
2018-11-16 08:37:19.243 ***** ERROR ***** [V7.2.7] REQUEST_URI = /tool/dynamicDialogDependency.php?id=undefined

When i check "Automatic run plan" and i hit "Calculate Activitie planning"

i get this error

2018-11-16 08:52:24.195 ***** ERROR ***** [V7.2.7] ERROR *****
2018-11-16 08:52:24.195 ***** ERROR ***** [V7.2.7] on file '/var/www/html/model/ProjectMain.php' at line (647)
2018-11-16 08:52:24.195 ***** ERROR ***** [V7.2.7] cause = Creating default object from empty value