Importing Compact Schedule Objects in IDF format


I cannot import my schedules in IDF format, despite doing the right thing (I think).

I have put my schedules in a IDF file (schedule.idf), in the right folder, which is:

Restart Rhino+GH, even reinstall Ladybug Tools, all do not help.

I keep having the following message:

Runtime error (ValueErrorException): "User Library Constant" was not found in the schedule library.

  line 41, in schedule_by_identifier, "C:\Program Files\ladybug_tools\python\Lib\site-packages\honeybee_energy\lib\"
  line 105, in schedule_object, "<string>"
  line 191, in script

Note: importing constructions/ materials works fine. I even tried to include the schedule in the construction file, but still it does not work.

The test schedule that I use is the following:

    User Library Constant,   !- Name
    on/off,                  !- Schedule Type Limits Name
    Through: 12/31,          !- Field 1
    For: AllDays,            !- Field 2
    Until: 24:00, 1.0;       !- Field 3

Is it possible that LBT does not like compact schedule? I swear that the previous versions could handle compact schedules.

I use Rhino 7, LBT 1.8.

Any help would be appreciated. Thanks.