I had a few error messages when I logged in, but it became a constant stream of errors once I ported to Oribos.

287x .../MissionReportButtonPlus/MissionReportButtonPlus.lua:264: attempt to index field '?' (a nil value)
[string "@MissionReportButtonPlus/MissionReportButtonPlus.lua"]:264: in function <.../MissionReportButtonPlus/MissionReportButtonPlus.lua:74>
[string "=[C]"]: in function RequestCallings' [string "@FrameXML/ObjectAPI/CovenantCalling.lua"]:103: in function Request'
[string "@FrameXML/ObjectAPI/CovenantCalling.lua"]:108: in function CovenantCalling_CheckCallings' [string "@FrameXML/Minimap.lua"]:947: in function HandleGarrisonEvent'
[string "@FrameXML/Minimap.lua"]:754: in function <FrameXML/Minimap.lua:752>

Locals:
self = MissionReportButtonPlusEventListenerFrame {
0 =
ShowMinimapButton_User = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1402
GarrisonLandingPageDropDown_Initialize = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1277
RedoButtonHooks = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1437
LoadData = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:404
GarrisonLandingPageDropDown_OnLoad = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1262
ShowMinimapButton = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1357
RegisterSlashCommands = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1573
SetButtonHooks = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1420
OnLoad = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:283
HideMinimapButton = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:1393
}
event = "COVENANT_CALLINGS_UPDATED"
callings =

{
}
(*temporary) = nil
(*temporary) = 111
(*temporary) = "Covenant callings received:"
(*temporary) = 0
(*temporary) = {
USER = -10
info = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:59
DEBUG = 10
debug = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:50
NOTSET = 0
DEVMODE = false
level = -10
INFO = 20
}
(*temporary) = -10
(*temporary) = 10
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = "attempt to index field '?' (a nil value)"
AddonID = "MissionReportButtonPlus"
_log = {
USER = -10
info = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:59
DEBUG = 10
debug = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:50
NOTSET = 0
DEVMODE = false
level = -10
INFO = 20
}
MRBP_EventMessagesCounter = {
}
MRBP_GARRISON_TYPE_INFOS = {
}
util = {
calendar = {
}
printVersion = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:84
GetTimeRemainingColorForSeconds = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:181
achieve = {
}
tcount = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:114
quest = {
}
map = {
}
expansion = {
}
CreateInlineIcon = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:141
GetTimeStringUntilWeeklyReset = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:197
garrison = {
}
covenant = {
}
poi = {
}
CreateInlineIcon1 = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:162
CreateInlineIcon2 = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:166
cprintEvent = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:103
threats = {
}
GetAtlasInfo = defined @MissionReportButtonPlus/MissionReportButtonPlus_Utils.lua:130
}
ns = {
dbg_logger = {
}
label = {
}
MRBP_IsAnyGarrisonRequirementMet = defined @MissionReportButtonPlus/MissionReportButtonPlus.lua:565
settingsMenuEntry = "99"
SLASH_CMD_ARGLIST = {
}
settings = <tab

I'll bet the problem is the change of Enum names documented here. I grepped my huge pile of addons for these and the only addons affected are Altoholic (in many modules) and MissionReportButtonPlus.

https://wowpedia.fandom.com/wiki/Enum.GarrisonFollowerType

I did a global replace and it fixed both addons.

The new and old names can be seen here: https://wowpedia.fandom.com/wiki/Patch_10.0.7/API_changes