OK, just in case someone else runs into this problem. I spoke to my local Kabota service rep and told him about the ERROR 60 "proportional valve in trouble..contact your local Kabota service dept". He went to his PDF file of trouble shooting section and concluded that I probably had a loose wire from the solenoid to the proportional valve, but couldn't tell me where anything was.
Crawled under tractor and right below the the steering column on the left side, under the clutch platform was the loose wire that been pulled loose by some small saplings I was pushing over with the loading bucket. The connector was broken up badly, but I managed to make the re-connection and used electrical tape to seal out all moisture and keep the wire attached to the proportional.
The wires location isn't the best place this could be, and the protective bracket that was bent forward wasn't even close to covering the proportional valve wire connector, and is too light to protect such an important component. Bottom line, if you're in tall weeds or saplings......take it easy!!!!