Start with the first reference that is returned by https://social.msdn.microsoft.com/Search/en-US?query=dtexec%20%22Exception%20has%20been%20thrown%20by%20the%20target%20of%20an%20invocation%22&emptyWatermark=true&ac=4 . Attempt to emulate the security context of SSIS by logging onto Windows as its startup account, and test your assembly under that security context. Also try a different account (such as the one that could register). If that does not help, post the complete error message.