before cutting out a whole quilt with a 'new to you' pattern it is always a good idea to cut out 1 block & put it together to check the sizes, construction, instructions----everyone makes mistakes sometimes- sometimes a designer has it right & the editor changes something- also when getting a pattern from a website it's a good idea to check the (pattern update-fix) page which is generally available that posts when errors that have been found & the 'fix'. i've bought really expensive patterns to find there are errors & had to visit the site to get the corrections- i've learned to never cut out a whole quilt before checking the math/doing a practice block. no point being angry with the source- it is a good idea to send a comment & your pics to show them the error so if it is not on the 'fix' page yet it can be.