Re: Ariane 5 vehicle has proven.a.. reliable workhorse,..92 launches out of 97 attempts.
Since I only remembered 2 failures I had to check
Out of those 5 those launches:
2 were explosives failures and total loss, total of 3 payloads (I think both were destroyed before they got a chance to destroy themselves)
1 was early first stage shutdown, not intended orbit howecer payloads met their objectives
1 was second stage early shutdown, 1 payload reached intended orbit using own engines. 2nd payload total loss
1 was wrong transfer orbit for 2 payloads as mentioned here, both will reach intended orbit
F9 has lost another payload which was a secondary on a NASA resupply flight to ISS due to early engine shutoff. It may of been able to get the secondary to the intended orbit but there was a risk to the resupply mission if they tried.
The first Ariane 5 launch and failure would of been a Reg story since it was due to a float conversion to an 16bit Integer causing an overflow error. The code was reused from the Ariane 4 and when it was designed for the Ariane 4 it was determined the overflow would never happen which was true for the Ariane 4.