This may be a difficult error to isolate, occurred when:
1. start GeoServer with default release data directory
2. Click layer preview, looks like establishing a session had bad luck and the jsessionid contained an invalid character
Also getting this error when I first start tomcat and go to the main localhost:8080/geoserver page
Hi Same issue here, I use http://SERVER/geoserver/j_spring_security_check to login and then it return that error
And I'm using the windows installer, so the web.xml file is it the one in webapps\geoserver\WEB-INF?
Issue still appearing with the latest 2.14 and 2.15M0 unfortunately. Only 2.13 does not have this issue. :-/
Eh, already two people showed interest in fixing it, one here, one in the linked issue, but no PR showed up yet....
Thanks Andrea I really appreciate this fix.