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

URI:/Content/194489/cache=20200106170127/NTLs%2520pensjonskonferanse.htm
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"