For those getting the

1x ...aceDoom_CooldownPulse\Doom_CooldownPulse.lua:99: bad argument #2 to 'strsplit' (string expected, got nil)
[string "=[C]"]: in function `strsplit'
[string "@Doom_CooldownPulse\Doom_CooldownPulse.lua"]:99: in function <...aceDoom_CooldownPulse\Doom_CooldownPulse.lua:88>
[string "@Doom_CooldownPulse\Doom_CooldownPulse.lua"]:244: in function `?'
[string "@Doom_CooldownPulse\Doom_CooldownPulse.lua"]:24: in function <...aceDoom_CooldownPulse\Doom_CooldownPulse.lua:24>

Locals:
(*temporary) = ","
(*temporary) = nil
(*temporary) = "string expected, got nil"

Error its just because of an empty blacklist, add something random in there (doesnt need to exist) and the error is fixed. I added lolthiserror and now it works fine, dont try to add something that makes sense or exists or it will blacklist an actual spell.

I think the proper fix for this issue is to change lines 228 to 243 from

    if (not DCP_SavedPerCharacter) then
        -- Unpack as shallow clone to avoid reset-to-default as considering the
        -- value assigned from the legacy saved variable below.
        DCP_SavedPerCharacter = {unpack(defaultSettingsPerCharacter)}

        -- Backwards compatibility: Assign from legacy saved value if exists.
        if (DCP_Saved.ignoredSpells) then
            DCP_SavedPerCharacter.ignoredSpells = DCP_Saved.ignoredSpells
        end
    else
        for i,v in pairs(defaultSettingsPerCharacter) do
            if (not DCP_SavedPerCharacter[i]) then
                DCP_SavedPerCharacter[i] = v
            end
        end
    end

to

    if (not DCP_SavedPerCharacter) then
        -- Unpack as shallow clone to avoid reset-to-default as considering the
        -- value assigned from the legacy saved variable below.
        DCP_SavedPerCharacter = {unpack(defaultSettingsPerCharacter)}

        -- Backwards compatibility: Assign from legacy saved value if exists.
        if (DCP_Saved.ignoredSpells) then
            DCP_SavedPerCharacter.ignoredSpells = DCP_Saved.ignoredSpells
        end
    end
    for i,v in pairs(defaultSettingsPerCharacter) do
        if (not DCP_SavedPerCharacter[i]) then
            DCP_SavedPerCharacter[i] = v
        end
    end