Error Code:

Error Code	7500529
Message	The value '{value}' is not a valid SAML ID. The ID must not begin with a number.
Remediation	Azure AD uses this attribute to populate the InResponseTo attribute of the returned response. The ID must not begin with a number, so a common strategy is to prepend a string like "id" to the string representation of a GUID. For example, id6c1c178c166d486687be4aaf5e482730 is a valid ID.