Not having access to Servicedesk Project(getting 405 (Method Not Allowed) error )

[Deleted user]

After upgrading the Jira software to the latest version (V9.0.1), it is not possible to access Servicedesk projects.
Also, Jira Service Management cannot be upgraded. (currently version: 4.20.1)

[Nic Brough -Adaptavist-]

Welcome to the Atlassian Community!

I'm afraid Jira itself won't throw a 405 error - this is a problem with the web-service.  This error usually suggests you are running Jira behind a proxy or load balancer, but it could be a Tomcat problem too (or if you're as old as I am, the application server you are runing a very old Jira on)

I'm afraid we can't help you much with this one without knowing more about your architecture.

[Benjamin Löschner]

Hello Nic, i have exactly the same issue @[deleted] describe. I just have a few areas like "Jira Service Management - Configuration" or just one Project i can't open after the newest update 9.0.0 and 9.0.1. My Jira Server is running on a Linux RHEL 8 Virtual Machine (Hyper-V). The Service itself is running behind a proxy. Could you try to continue to help us ins this case?

[Benjamin Löschner]

Solved it! THe Solution that worked can be found here: https://community.atlassian.com/t5/Jira-Software-questions/HTTP-Status-405-Error-after-upgrade/qaq-p/2092275 

Its just neccessay to update also Jira Service Desk.