What could be the possible reasons for "Access reading location or Access writing location"

Question

I am having issues with access violation. below are the two examples.

Case1: When the following code had few assignments and few function calls. the access violation comes while assignment statement execute.

Case2: after rearranging the code, putting the assignment statements before the calls since that does not have any impacts on the implementation. the access violation location and type changed.

Now I can see in assembly it is there both time while working with edp regiseter. could there be anything I am missing or overstepping on? Would appreciate some help here a lot!

PS: I cannot share the code because of company policies, but if any further explanation is required, I will try whatever is possible to add.