receiving null pointer error when accessing config object from uvm_do_with

Hi,

i have an agent (uvm_agent) which has a config object (uvm_object) which holds the agent's configurations.

i am setting this config from the environment and getting it inside the agent.

in the agent i am setting this config for everyone to see (*).

i have a sequence for this object that get's this config object.

everything works ok so far and i am able to access all the configurations from the config object inside the sequence.

the problem starts when i try to create constrained transactions (`uvm_do_with) with the constraints taken from this config object.

then i get a null pointer error.

the error:

so i can access a certain field from the sequence but when i try to set it as a constraint i get an error.

some code from the sequence (this is only part of the code):