Inverter Shuts down at night, but doesn't start again in the morning.

New to PV, but gather parts to build my own system as a test. Installed yesterday and had it up and working beautifully. Then as evening turned to night, PV output dropped as expected until eventually the Inverter shut down completely. 

This morning, I kept an eye on the monitoring software to see when it would begin to generate power again, but by 11 there was nothing. Hopped up on the roof and the RED light was on which means:

a. Islanding protection;

b.Over-temperature protection;

c.Over / low AC voltage protection;

d. Over / low DC voltage protection;

e.Fault

I turned off the AC side, then disconnected all 4 PV panels until the red light went off, Connected them back again and turned on the AC. After a few seconds the red light went out and software instantly reported 400+ W power generation. 

So my question is, what would cause the inverter not to start as normal in the morning? 

WVC-1200 Inverter with wireless modem to monitor

KDM Monitoring software

Various 285w panels

Cheers

Neil

damp in connectors is favourite problem for failing to start in morning which normally comes up as Riso or low insulation resistance. Are you in UK or USA?