You might have mistyped some letter the first time you tried.
Any one typographic error will render the seed phrase invalid that will make the 'next' button unclickable.
This was when Android Electrum generated the seed phrase for me
This was when I proceeded and it did not work
This was when I went back to use I already have a seed and it worked.
I do not have bitcoin on the wallet and I have deleted it to generate another one because I exposed the seed phrase.
hosseinimr93 talked about it correctly. I hope this would be corrected in the next update because it can confuse some people.