Filling model objects in list obj throwing exception

Idk which type of  Model objects do you have, yet as far as i can guess a normal object is usually not greater than 2GB,

if any of your model object is Greater than 2GB then .Net framework will throw Out of Memory exception, if your target framework <=4.5, for .Net Core you have little extra memory given for a single object.

however you can change this default behaviour anytime by using below code

 

go to Project properties -> Build tab and be sure to set x64 as a Platform target.

or try below.

otherwisw there may may be memory leak you have to check totalmemorysize consumed, please post your code here