Thank you. On this website, I do not always get to give good news, and this is one of these times.
If you live outside USA for 6 months to a year, you may have the greencard voided upon attempt to reenter, if you cannot show ties to USA such as an address in USA, bank account, school/work, etc.
Anything over a year, and the voidance is almost guaranteed. If you have been out since 2011, your greencard is now likely void and reentry would be denied. The only option is to attempt to file an SB-1 application, asking to be let back in. See HERE. However you'd have to show that you were out if the USA due to circumstances beyond your control.
If this is no successful (or if you decide it is not likely going to be), then the greencard process has to be filed form the beginning for you.
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