Fresh install of KSP, no other mods, just RCSBuildAid

[ ] PhysicsGlobals: Loading database
[ ] Load(Assembly): /ModuleManager.2.6.8
[ ] AssemblyLoader: Loading assembly at {KSPDIR}\GameData\ModuleManager.2.6.8.dll
[ ] AssemblyLoader: KSPAssembly 'ModuleManager' V2.5
[ ] Load(Assembly): RCSBuildAid/Plugins/RCSBuildAid
[ ] AssemblyLoader: Loading assembly at {KSPDIR}\GameData\RCSBuildAid\Plugins\RCSBuildAid.dll
[ ] Load(Assembly): RCSBuildAid/Plugins/RCSBuildAidToolbar
[ ] AssemblyLoader: Loading assembly at {KSPDIR}\GameData\RCSBuildAid\Plugins\RCSBuildAidToolbar.dll
[ ] AssemblyLoader: Loading assemblies
[ERR ] AssemblyLoader: Exception loading 'RCSBuildAidToolbar': System.Reflection.ReflectionTypeLoadException: The classes in the module cannot be loaded.
at (wrapper managed-to-native) System.Reflection.Assembly:GetTypes (bool)
at System.Reflection.Assembly.GetTypes () [0x00000] in :0
at AssemblyLoader.LoadAssemblies () [0x00000] in :0

Additional information about this exception:

System.TypeLoadException: Could not load type 'RCSBuildAid.Toolbar' from assembly 'RCSBuildAidToolbar, Version=0.7.2.26995, Culture=neutral, PublicKeyToken=null'.

It seems to be working 'correct' ingame but ...

if you aren't going to use blizzy's toolbar, then you don't need RCSBuildAidToolbar.dll and you can delete it safely.