We actually just saw this issue on 4.1.1
Just got it on Event Store 188.8.131.52
Can you guys provide more details either here or to support? Most likely it is a random occurrence as not much has changed but would prefer to investigate.
It can be a part of the FAQ, the reason was mentioned in this group. We have that as well.
Say, we made a projection “xxx” that projects to a stream “xxx-proj”.
Then, we delete this projection and create a new projection “yyy” that writes to “xxx-proj”.
As a result, “yyy” fails with “Projection Faulted: An event emitted in recovery differ from the originally emitted event”.
In our case, we should have modified the “xxx” with the new code, instead of deleting it and making a new projection that writes to the same stream.
The overall solution was to write to another stream or remove the “xxx-proj” stream and then the new projection starts working.