Been getting errors even after updates.

258x Interface/AddOns/RaiderIO/core.lua:7782: attempt to call method 'RegisterEvent' (a nil value)
[string "@Interface/AddOns/RaiderIO/core.lua"]:7782: in function OnLoad' [string "@Interface/AddOns/RaiderIO/core.lua"]:715: in function Load'
[string "@Interface/AddOns/RaiderIO/core.lua"]:4033: in function <Interface/AddOns/RaiderIO/core.lua:4025>
[string "@Interface/AddOns/RaiderIO/core.lua"]:4065: in function callbackFunc' [string "@Interface/AddOns/RaiderIO/core.lua"]:950: in function SendEvent'
[string "@Interface/AddOns/RaiderIO/core.lua"]:885: in function <Interface/AddOns/RaiderIO/core.lua:881>

Locals:
self =

{
index = 19
Enable = defined @Interface/AddOns/RaiderIO/core.lua:735
GetDependencies = defined @Interface/AddOns/RaiderIO/core.lua:777
OnDisable = defined @Interface/AddOns/RaiderIO/core.lua:809
HasDependencies = defined @Interface/AddOns/RaiderIO/core.lua:760
OnLoad = defined @Interface/AddOns/RaiderIO/core.lua:7754
SetLoaded = defined @Interface/AddOns/RaiderIO/core.lua:705
IsLoaded = defined @Interface/AddOns/RaiderIO/core.lua:725
enabled = true
loaded = true
id = "DropDown"
OnEnable = defined @Interface/AddOns/RaiderIO/core.lua:805
Disable = defined @Interface/AddOns/RaiderIO/core.lua:745
SetDependencies = defined @Interface/AddOns/RaiderIO/core.lua:755
IsEnabled = defined @Interface/AddOns/RaiderIO/core.lua:730
SetEnabled = defined @Interface/AddOns/RaiderIO/core.lua:720
Load = defined @Interface/AddOns/RaiderIO/core.lua:710
CanLoad = defined @Interface/AddOns/RaiderIO/core.lua:7750
}
(*temporary) = nil
(*temporary) = {
_callbacks = {
}
_cdropdowns = {
}
}
(*temporary) = "OnShow OnHide"
(*temporary) = defined @Interface/AddOns/RaiderIO/core.lua:7691
(*temporary) = 1
(*temporary) = {
index = 19
Enable = defined @Interface/AddOns/RaiderIO/core.lua:735
GetDependencies = defined @Interface/AddOns/RaiderIO/core.lua:777
OnDisable = defined @Interface/AddOns/RaiderIO/core.lua:809
HasDependencies = defined @Interface/AddOns/RaiderIO/core.lua:760
OnLoad = defined @Interface/AddOns/RaiderIO/core.lua:7754
SetLoaded = defined @Interface/AddOns/RaiderIO/core.lua:705
IsLoaded = defined @Interface/AddOns/RaiderIO/core.lua:725
enabled = true
loaded = true
id = "DropDown"
OnEnable = defined @Interface/AddOns/RaiderIO/core.lua:805
Disable = defined @Interface/AddOns/RaiderIO/core.lua:745
SetDependencies = defined @Interface/AddOns/RaiderIO/core.lua:755
IsEnabled = defined @Interface/AddOns/RaiderIO/core.lua:730
SetEnabled = defined @Interface/AddOns/RaiderIO/core.lua:720
Load = defined @Interface/AddOns/RaiderIO/core.lua:710
CanLoad = defined @Interface/AddOns/RaiderIO/core.lua:7750
}
(*temporary) = "attempt to call method 'RegisterEvent' (a nil value)"
unitOptions = {
1 = {
}
2 = {
}
}
L = {
SHOW_LEADER_PROFILE = "Allow Raider.IO Profile Tooltip Modifier"
RAID_BOSS_FSFO_1 = "Vigilant Guardian"
ENABLE_AUTO_FRAME_POSITION = "Position Raider.IO Profile Frame Automatically"
INVERSE_PROFILE_MODIFIER = "Invert Raider.IO Profile Tooltip Modifier"
DUNGEON_SHORT_NAME_SD = "SD"
UNLOCKING_PROFILE_FRAME = "Raider.IO: Unlocking the M+ Profile Frame."
DB_MODULES_HEADER_MYTHIC_PLUS = "Mythic+"
GUILD_LF_PVP = "Recruiting PvP Players"
DUNGEON_SHORT_NAME_PF = "PF"
RAID_BOSS_FCN_5 = "Sun King's Salvation"
ENABLE_NO_SCORE_COLORS = "Disable All Mythic+ Score Colors"
PROFILE_TOOLTIP_ANCHOR_TOOLTIP = "Lock Raider.IO Profile Frame or enable Automatic Positioning in order to hide this anchor."
CURRENT_MAINS_SCORE = "Main's Current M+ Score"
RAID_DIFFICULTY_NAME_MYTHIC = "Mythic"
RAID_BOSS_FCN_10 = "Sire Denathrius"
DUNGEON_SHORT_NAME_HOA = "HOA"
RAIDERIO_MP_SCORE = "Raider.IO M+ Score"
ENABLE_SIMPLE_SCORE_COLORS = "Use Simple Mythic+ Score Colors"
SHOW_SCORE_IN_COMBAT_DESC = "Disable to minimize performance impact while hovering players during combat."
COPY_RAIDERIO_PROFILE_URL = "Copy Raider.IO URL"
CANCEL = "Cancel"
CHARACTER_LF_GUILD_SOCIAL = "Looking for Social Guild"
SHOW_CURRENT_SEASON_DESC = "Shows the player's current Mythic+ season score as the tooltip headline."
TIMED_20_RUNS = "Timed 20+ Runs"
RAID_BOSS_FSFO_8 = "Anduin Wrynn"
TIMED_15_RUNS = "Timed 15+ Runs"
ALLOW_IN_LFD = "Allow in Dungeon Finder"
SHOW_RAIDERIO_PROFILE = "Show Raider.IO Profile Tooltip"
COPY_RAIDERIO_RECRUITMENT_U

This is a very strange error, because what it says is that it failed to run code that, at that point, we expect to be runnable.

I have to ask, since sometimes we update again or restart the game and suddenly something like this goes away, but since the issue is open I wanted to ask if you still have the error occur on your end.

If you still have the error, and have tried to re-install the RaiderIO addon just to see if it helped (or update it as that also would do the trick), could you send me your list of addons that you play with? I could see if something odd is going on from code located in another addon affecting your situation.

I can recommend just test without any addons, other than RaiderIO, just to see if the issue stays or goes away, as an addon or a specific WeakAura could technically be involved causing this error as well.