When you alter a trigger name, the update does not propagate to the dependency. So it says "Depends on" "Old triggername"
I've added two printscreens of this issue

As you can see in BugTriggers.jpg, the trigger with severity warning is dependant on the average trigger. Yet it says: depends on:
C_Template_SNMPv2_Disk_1 : C_Template_SNMPv2_Disk_1 > Disk 1 > 95 %. This is a non existant trigger.

If i wish to change the dependency then i can only choose the two old names. i guess there is some table inconsistency here.
between the name of the dependant trigger and the accual triggername.
I've only just noticed this, i've upgraded this morning to 1.8.6. My guess is this affect all 1.8.x. versions.

I have one standalone and a DM setup, and everywhere i have the same issue.

This is something that should be checked as it could lead to bigger issues...