Befor -I use yaf 1.9.1.8 Final
-I use other user (I have main project,It have forum)
-I use yafUserClass.cs
-I config yetnet
TinyGecko.YAFIntegration.dll
TinyGecko.YAFIntegration.yafUserClass
But now
-I use yaf 1.9.3
-I have problem other user.
-I have use other user same in v 1.9.1.8
-I hame error

Object reference not set to an instance of an object

in web config

Which admin page? Can you explain where you got this error and provide the full Exception information?