Crack in shower tray

I am currently in utter despair as everything seems to be going wrong in the van at moment.
07 Nuevo and last hab check in Willersey showed 49% damp. Agreed to take it in for extensive work (not clear what problem is) back to Willersey knowing it will be hundreds. Still not sure doing right thing but they know the van. A local caravan hospital would look at it for half the hourly rate of Willersey but as its likely to be extensive taking apart of van a bit unsure they would be confident to do a good job.

Anyway used as day van with friends and somehow flushed water from toilet came into shower tray. Removed black mat to dry out and toilet was used couple of times without mat in. Then noticed a crack around one of the shower tray plug holes (semi circle) Absolutely horrified. Has anyone else had this and how have you sorted it.

My husband is really quite ill and we had thought to possibly sell the van but whether we keep or sell it will have to be sorted although I will hang onto it until the bitter end!!

Really value any thoughts, advice shared experience.

Really gutted! Love my Nuevo!!

Not very Happy Helen. 

That hole is a weak point. This is how I fixed it.
https://www.autosleeper-ownersforum.com/t27303-shower-tray-weak-point
But an alternative would be to cut a reinforcing ring, like a big washer, out of a cheap polythene plate.
Of course it means taking the drain out, which is a simple task.
Al.

You mention about taking the drain out - is that done from above the shower tray or underneath somehow?

Just as an aside is the heavy black shower tray may (in the mark 1 Nuevo anyway) supposed to be down all the time. We have ours down except for when showering and then remove it - is this what we are meant to do? Just thought crack may not have occurred if toilet hadn't been used with black mat not in and in shoes.

The heavy black mat is supposed to be down all the time, especially when showering, it protects the tray. We take ours out at the end of a trip to give everything a deep clean.
The drain is easily removed by unscrewing the central screw, much like many domestic installations, then the bottom half can be removed from below the van, no need to disconnect the pipe.
Al.

Thanks for that. Really appreciate your advice.
Need to look at this after the damp is sorted.

Thanks HH