An invalid XML character (Unicode: 0x1a) was found in the element content of the document

We're getting an "An invalid XML character (Unicode: 0x1a) was found in the element content of the document" error from a BaseX REST API PUT request We using BaseX 8.6.7 ( I realize that BaseX 8.6.7 isn't the latest version). Is this a user error or a BaseX problem? If it's user error, how would I fix the error. If it's a BaseX problem, is it fixed in a more recent BaseX version.

Character 0x1A is indeed not allowed in an XML document. See e.g. https://www.w3.org/TR/REC-xml/#charsets One reason this can happen is if a document is in some character set, such as a DOS codepage or early Apple charset, that (mis-)uses some of the control characters, such as this one, to be printable characters. Anotheris conversion errors, and another is attempts to include binary data. In other words it's usually a file encoding problem. If the document doesn't actually contain a byte of that value, though, it's another problem...