Error 500 org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL contained a potentially malicious String "%25"

HTTP ERROR 500 org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL contained a potentially malicious String "%25"

URI:	/Content/204504/cache=20200506165512/H%25F8ring%2520KD_NOU%2520Ny%2520lov%2520om%2520universiteter%2520og%2520h%25F8gskoler.pdf
STATUS:	500
MESSAGE:	org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL contained a potentially malicious String "%25"
SERVLET:	dispatcherServlet
CAUSED BY:	org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL contained a potentially malicious String "%25"