hi im ricky im very furmilar with ur unit used to work on kubota, first thing i want u to check is ur free play on clutch it should be 1.5 inch to 2 inches, u can check this with the tape messure and put it beside the clutch pedal and press it till u feel a bit of resistance if need adjust you needi think its 14 mm wrench and u should see a turn buckel on left side with 2 jamm nut turn that turn bukel in till you get ur 1.5 to 2 inchs free play,
if u dont feel any restance then unfortntly it will have to be split something has broke on ur fork and release bearing.
if u do feel resetance and free play is good than ur disc is froze on fly wheel u can try to free it by locking ur breaks up while pedals down and high gear. if can not free it up you have to split it
i hope this helps u