It sounds like something has gotten corrupted, and you might benefit from a fresh download, maybe download & restart.
However, there is a way to enable quick save/load with the keyboard. The file below will let you Quick Save with `F5` and Quick Load with `F6`. In the ./game folder, name a file something like "quick_keys.rpy" and put the following in it:
init 999 python:
try:
config.underlay[0].keymap['quickSave'] = QuickSave()
config.keymap['quickSave'] = 'K_F5'
config.underlay[0].keymap['quickLoad'] = QuickLoad()
config.keymap['quickLoad'] = 'K_F6'
except:
pass