If I import this package in a new project, I get no problems at all.

But, when I try to import it into my existing project (that had the 5.0.4 version of the SDK), after the importing finished, I get the followin error message:

```
Unhandled Exception: Mono.CSharp.InternalErrorException: Internal error

  at Mono.CSharp.MethodGroupExpr.IsApplicable (Mono.CSharp.ResolveContext ec, Mono.CSharp.Arguments& arguments, Int32 arg_count, System.Reflection.MethodBase& method, System.Boolean& params_expanded_form) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.MethodGroupExpr.OverloadResolve (Mono.CSharp.ResolveContext ec, Mono.CSharp.Arguments& Arguments, Boolean may_fail, Location loc) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.Invocation.DoResolveOverload (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.Invocation.DoResolve (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.Expression.Resolve (Mono.CSharp.ResolveContext ec, ResolveFlags flags) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.Expression.Resolve (Mono.CSharp.ResolveContext ec) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.ExpressionStatement.ResolveStatement (Mono.CSharp.BlockContext ec) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.StatementExpression.Resolve (Mono.CSharp.BlockContext ec) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.Block.Resolve (Mono.CSharp.BlockContext ec) [0x00000] in <filename unknown>:0 

  at Mono.CSharp.ToplevelBlock.Resolve (Mono.CSharp.FlowBranching parent, Mono.CSharp.BlockContext rc, Mono.CSharp.ParametersCompiled ip, IMethodData md) [0x00000] in <filename unknown>:0 

```

Anyone have any idea why this is happening?

(As extra information, in my project I have Itween & EasyTouch integrated)