Extra Liner??

I thank you all in advance for any assistance you can provide me.

I have spent the last couple weeks putting up a 21' round that was my Uncles. I bought a new liner, frame is up and leveled. Everything appears and measures correctly.

So, I go to put the new liner in today. Its a beaded liner.

Problem..... I have an extra 10" of liner when I get around!! I've measured every post to post around the pool and its spaced at a dead on 21'

Any ideas to get this extra spread out evenly so I can proceed?

Thank you!