A single & character causes failures like this:
RuntimeError (Failed to clean XML: The reference to entity "ix" must end with the ';' delimiter.):
In a note field there is a link with a URL as follows:
It's choking on the &ix=whatever.
Or any string with an ampersand like J&J or W&S and so on...
This bug fix (which looks to be in the 2.5.1 release) looks to be for a similar issue involving ampersands: https://github.com/archivesspace/archivesspace/issues/972
This appears to still be an issue. Adding a note with the text "&ersand" in the staff UI yields a PUI note display of "&ersand". Tested in test.archivesspace.org
I was able to & by using & and "&" by myself. From Josh's comment it seems like it may also be possible to enter an & using & as well? Tested in test.archivesspace.org