When I open the friends list or guild list on both SoD and hardcore classic, I got this error :

Message: ...dOns/ProjectAzilroka/Modules/EnhancedFriendsList.lua:80: attempt to call method 'SetGradientAlpha' (a nil value)
Time: Tue Dec 5 11:31:30 2023
Count: 11
Stack: ...dOns/ProjectAzilroka/Modules/EnhancedFriendsList.lua:80: attempt to call method 'SetGradientAlpha' (a nil value)
[string "=[C]"]: in function SetGradientAlpha' [string "@Interface/AddOns/ProjectAzilroka/Modules/EnhancedFriendsList.lua"]:80: in function SetGradientColor'
[string "@Interface/AddOns/ProjectAzilroka/Modules/EnhancedFriendsList.lua"]:203: in function <...dOns/ProjectAzilroka/Modules/EnhancedFriendsList.lua:108>
[string "=(tail call)"]: ?
[string "=[C]"]: in function FriendsFrame_UpdateFriendButton' [string "@Interface/FrameXML/FriendsFrame_Shared.lua"]:1137: in function FriendsFrame_UpdateFriends'
[string "@Interface/FrameXML/FriendsFrame_Shared.lua"]:530: in function FriendsList_Update' [string "@Interface/FrameXML/FriendsFrame_Shared.lua"]:273: in function <Interface/FrameXML/FriendsFrame_Shared.lua:272> [string "=[C]"]: in function Show'
[string "@Interface_Vanilla/FrameXML/UIParent.lua"]:2160: in function SetUIPanel' [string "@Interface_Vanilla/FrameXML/UIParent.lua"]:2005: in function ShowUIPanel'
[string "@Interface_Vanilla/FrameXML/UIParent.lua"]:1873: in function <Interface_Vanilla/FrameXML/UIParent.lua:1869>
[string "=[C]"]: in function SetAttribute' [string "@Interface_Vanilla/FrameXML/UIParent.lua"]:2652: in function ShowUIPanel'
[string "@Interface/FrameXML/FriendsFrame_Shared.lua"]:962: in function `ToggleFriendsFrame'
[string "TOGGLESOCIAL"]:1: in function <[string "TOGGLESOCIAL"]:1>

Locals: (*temporary) = defined =[C]:-1

You can temporarily resolve this by making the following changes:

1 - Open:
C:\Program Files (x86)\World of Warcraft_classic_era_\Interface\AddOns\ProjectAzilroka\Modules (or whatever your path is)

2 - Open EnhancedFriendsList.lua

3 - Search for lines 79-82 and delete them:
else
button.Left:SetGradient("Horizontal", color1, color2)
button.Right:SetGradient("Horizontal", color2, color1)