Requiem Shard

It seems that toxins using the conflagration effect don't work. You can craft such a toxin and the effects show up in the toxin gump, but when used there seems to be no effect at all even if you have the Insidious Incendiaries trait from Alchemy tree.

They do work just not as advertised. Instead of the DoT described in the tool it's an onhit property. You'll see every hit an extra dmg being applied from the conflaguration. Still a bug in that it's an onhit lump of damage instead of a DoT effect but it is still an effective toxin.