This kind of message is primarily a development aid, and should not be seen by the user in production status. A 'tag' is an internally generated value that represents a unique value. After generation, the new tag is internally verified. There are many reasons why tag verification could conceivably fail, but the return code indicates this to Informatica Global Customer Support.
The internal request is abandoned, and processing ends.
Contact Informatica Global Customer Support for support, quoting the full text of the message.