https://itch.io/t/4370963/save-files-of-016-cannot-load-to-017
If you cannot click load button, one or more files in your save folder have expressions the game cannot read, or are missing stuff the game expects to find on load. Game seems to scan all files in the save folder, and if even one is not up to par with what it wants, it won't load anything, period.
And I suppose it won't let you start a new game cuz that would make a new auto-save, which would be inaccessible due to the policy of not going near the save folder when there's stuff in it the game won't like...vicious circle, see^^.
I only started playing on this most recent version, but just seeing all the new races added in alpha 0.17 makes me think old 0.16 save files lack a ton of stuff compared to saves from this version. So no, old save files from alpha 0.16 will not work anymore.
Kick all old files from your save folder, try to start a new game, if it works save and see if it loads that file.
EDIT: And Happy new year all^^.