This is the safest way to manually flash Belle FP1.
The #1 problem Nokia E7 owners face today is the error when trying to install .sis or .sisx apps. This happens because all Symbian certificates were set to expire in 2013-2020. nokia e7 software update
The Nokia E7 was supposed to be the crown jewel of the business world. Sharing the same 4-inch AMOLED "CBD" (ClearBlack Display) as the N8, it added a full four-row QWERTY keyboard. However, unlike the N8, the E7 shipped with – a buggy, laggy operating system that infuriated early adopters. This is the safest way to manually flash Belle FP1