Errors:

21x Peddler/Peddler.lua:542: attempt to call global 'IsAddOnLoaded' (a nil value)
[string "@Peddler/Peddler.lua"]:542: in function <Peddler/Peddler.lua:541>
[string "@Peddler/Peddler.lua"]:592: in function <Peddler/Peddler.lua:586>

Locals:
(*temporary) = nil
(*temporary) = "Baggins"
(*temporary) = "attempt to call global 'IsAddOnLoaded' (a nil value)"
usingDefaultBags = false

and

1x Peddler/Peddler.lua:646: attempt to call global 'IsAddOnLoaded' (a nil value)
[string "@Peddler/Peddler.lua"]:646: in function <Peddler/Peddler.lua:636>

Locals:
self = Frame {
}
event = "ADDON_LOADED"
addonName = "Peddler"
(*temporary) = nil
(*temporary) = "Baggins"
(*temporary) = "attempt to call global 'IsAddOnLoaded' (a nil value)"
peddler = Frame {
}
countLimit = 400
Baggins = nil
markCounter = 1

Looks like "IsAddOnLoaded(name)" was depreciated in favor of "C_AddOns.IsAddOnLoaded(name)" - I don't know enough to correctly update.

Hi old chap!

Thanks as always for the report. I'm currently on holiday, but hopefully managed to upload a fix. Let me know how well it works!

No more errors in my bugsack, and it seems to be working. Thank you!!