I have got all the bits it says I need for the mod aka JEI and the CodeChickenLibs but every time I try I get this issue
crash-2017-08-06_02.03.58-client.txt

not sure what to do now

1.12 is not ready yet. I have changes locally that im waiting on feedback to see if they are all good then a release will be pushed.

could I suggest that you put that 1.12 is not supported in the readme.md at this time then when it is you can remove it

Well its literelly about to be pushed, so that would be pointless :D

@covers1624 maybe it would benefit you to create a placeholder issue telling people that NEI for MC 1.12 is not ready for release yet?
Because apparently it hasn't been pushed yet.