Unable to run ASP.NET Core application with HTTP/3 enabled on a Plesk server

Gilson Siqueira

Updated June 26, 2024 16:24

kb: technical

Symptoms

A working ASP.NET Core application stops working after enabling HTTP/3 as per documentation with errors 400 and 499.

The issue is related to the bug PPPM-14435: HTTP/3 breaks phusion passenger implementation of .NET toolkit.

Until the bug is fixed, there is one workaround:

Connect to the server via SSH
Edit file /etc/nginx/plesk.conf.d/vhosts/example.com.conf (where example.com is the affected domain)
Add the Host line as such:

CONFIG_TEXT: #extension dot-net begin
location / {
passenger_enabled on;
passenger_set_header Host $host:$server_port;
Save the file and restart nginx:

# systemctl restart nginx