Local background subtraction ERROR

[jortiz12]

Hello,
I'm trying to do apperture photometry using a circular apperture, and subtracting the background in a surrounding annulus as described in the tutorial.

My data has shape (436,437), and I'm just testing one apperture (i.e. center[0] and center[1] are scalars in my test case below). However I get the following error,

I understand that 190532 = 436*437, but don´t understand the reshape-related error.

Any advice would be much appreciated.
Kind Rgds,
Jose