Dell X1026P can not access internet

Dear All,

I have a problem with Dell X1026 switch. There is an initial condition topology :

With this topology the SW2 can not access the internet. In the PC after connected to the SW2 the internet is suddenly no internet, and I wait an hour, still no internet access.

But after I change to this topology (with the same cable) :

With this topology the PC when connected to SW2 can access the internet. For more information I give you the pieces of my configuration in core switch.

For CoreSwitch1 : here

For CoreSwitch2 : here

My question is, can I use the initial topology and the internet run well like my last topology ? What's wrong with my configs ?

Please kindly need your help.