We recently saw that messages on MSMQ are being sent to the error queue due to additional characters. This looks very similar to an old issue with Appmon: https://community.dynatrace.com/questions/92449/msmq-messages-being-sent-to-error-queue.html
The OneAgent is now disabled and the problem disappeared, it looks like it started after switching on the ".NET messaging MSMQ" feature.
Has anyone else observed similar issues?
Update: related post for our issue, posted by someone from the responsable team in the company: https://discuss.particular.net/t/random-characters-added-at-the-end-of-headerinfo/2066
Unfortunately we have not been able to investigate this further with Dynatrace engineers, due to time constraints on the customer's side.
I can offer 2 different work-arounds:
(Quoted from the answer in the second link)