I used to use an empty tagset definition to assure plugin-init runs at Lightroom startup, perhaps starting background / init tasks.
This is no longer working in Lr4 (.1RC2) - win7/64.
Seems Adobe was hep to simply saying: "Run init module at startup" in Info.lua somehow, but until we get an SDK which has that, defining non-empty metadata or tagsets will still do it.
I still use this technique and it seems to be working fine for me for LR2 through till the latest LR4 RC.
How exactly are you defining this tagset? Im using a line in Info.lua:
LrMetadataTagsetFactory = "MetadataTagsetNone.lua",
and MetadataTagsetNone.lua essentially contains the following line:
My MetadataTagsetNone does contain a couple of lines of debugging code but nothing important.
I expect you have done somthing similar. Maybe its worth a retest?
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