How to solve: “exception was thrown by the target of invocation” C#

Question

C#

Every time I run my porgram I get this exception:

But when I run in debug mode, there i

Answer 1

For me, had some null references in the OnLoad() of a XAML project (and it threw OP's nebulous error). Just as Lasse Vågsæther Karlsen answered, looking at the inner exception's stacktrace got me to the line number.