doesn't work because ABS_B1800 is a virtual variable which is resolved by looking in the master. Instead the code doesn't think it's virtual and doesn't find the variable.
There's a list of all the virtual variables, virtualVariables.txt, which did not have OMNI2_H0_MRG1HR listed as a virtual variable. This caused the problem.
The CDAWeb support doesn't check the masters to see if virtual variables exist in the master file. For example, in Autoplot
vap+hapi:http://localhost:8080/HapiServer/hapi?id=OMNI2_H0_MRG1HR¶meters=Time,ABS_B1800&timerange=1998-09-06+through+2024-05-09
doesn't work because ABS_B1800 is a virtual variable which is resolved by looking in the master. Instead the code doesn't think it's virtual and doesn't find the variable.