899 Gearbox Problem

Hey Lads, New Irish member living in Australia.
A couple of weeks ago I picked up my very first Ducati, a 2015 899 with only 800ks on the clock.
It had a very low speed slide and as a result only had minor scratching to the lhs fairing.
I purchased it from an Auction, this auction company wont even let you start the bike let alone ride it before purchase so that alone was a gamble but i had to have it.
After purchase i checked oil level and quality and it was perfect, so i started it up. Sounded brilliant.
After a few more checks i took it out for a drive and it drives brilliantly, apart from 1 thing.
It shifts up through the gears seamlessly but i cant get fifth gear. Its as if their is nothing their.
The shift lever rises up completely and their is no resistance their at all.
I have had the bike out a 5 or 6 more times and still nothing, hot or cold.
If I was to have a guess with my limited knowledge, id say its like a selector fork not engaging 5th or something.
Any Help and info greatly appreciated.
Would love to get this sorted.
Cheers
Pat

 

Nobody has any experience with this? Or info on where i should start to look?
Cheers

 

Thanks for your reply mate.
So im hoping a strip down of a 899 to access the gearbox is simular to my Aprilia rs250 in the way the its actually a cassette type gearbox and just slots out of the engine case. But maybe this is wishfull thinking?
Cheers