Cant Select created worlds only create

So this might not get awnserd but i want to play whit a modpack that uses 1.7.10 but the problem lies whit windows 10 or minecraft 1.7.10

why well becuse i run a clean version of 1.7.10 whit same problem (not being able to select existing saved games. only make new worlds)

when i started 1.12 it worked pefectly fine.

any advice what to do?