Tried to install the updated plugin and received this error.

Arkan was compiled successfully in 1982ms

[Arkan] Added field to config: Plugin variables/NRProcessTimer

[Arkan] Added field to config: Plugin variables/EPSILON

[Arkan] Added field to config: Plugin variables/projectileTrajectoryForgiveness

[Arkan] Added field to config: Plugin variables/hitDistanceForgiveness

[Arkan] Added field to config: Plugin variables/minDistanceAIMCheck

[Arkan] Added field to config: Plugin variables/isDetectAIM

[Arkan] Added field to config: Plugin variables/isDetectNR

[Arkan] Added field to config: Plugin variables/debugMessages

[Arkan] Added field to config: Plugin variables/autoSave

[Arkan] Added field to config: Plugin variables/drawTime

[Arkan] Added field to config: Plugin variables/NRViolationAngle

[Arkan] Added field to config: Plugin variables/NRViolationScreenDistance

[Arkan] Added field to config: Plugin variables/playerEyesPositionToProjectileInitialPositionDistanceForgiveness

[Arkan] Added field to config: Plugin variables/isRicochetCheck

[Arkan] Added field to config: Discord settings/Enable Discord Notifications

[Arkan] Added field to config: Discord settings/Discord Webhook URL

Failed to initialize plugin 'Arkan v1.0.10' (NullReferenceException: Object reference not set to an instance of an object) at Oxide.Plugins.Arkan.LoadVariables () [0x00235] in <9214a764b6a24e6685c1376d7f595c2a>:0 at Oxide.Plugins.Arkan.Init () [0x00000] in <9214a764b6a24e6685c1376d7f595c2a>:0 at Oxide.Plugins.Arkan.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00051] in <9214a764b6a24e6685c1376d7f595c2a>:0 at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9affce1cd15c4ec183941adef8db1722>:0 at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <4452f821def6406d834e4149849fe7ea>:0 at Oxide.Core.Plugins.CSPlugin.HandleAddedToManager (Oxide.Core.Plugins.PluginManager manager) [0x00043] in <4452f821def6406d834e4149849fe7ea>:0

Antidote

Try to delete all old configuration and language files:
oxide/config/Arkan.json
oxide/data/Arkan/config/AIMBodyParts.json
oxide/data/Arkan/config/weaponsConfig.json
oxide/lang/en/Arkan.json
oxide/lang/ru/Arkan.json

Then reinstall or reload Arkan.
o.reload Arkan

Looks like the config should be enough in this case.

Thank you. I deleted the oxide/config/Arkan.json and reloaded the plugin but received the same error. After i deleted all old *.Arkan.json file, it loaded correctly.