Unable to edit page behind proxy (java.lang.ClassCastException)

[Rumotameru]

I've set up simple reverse nginx proxy for Confluence (7.13.18) using standart documentation (redirecting from 443 to 9080)

server {

 server_name paywiki;

 

 listen 443 default ssl;

 ssl_certificate /etc/nginx/ssl/nginx.crt;

 ssl_certificate_key /etc/nginx/ssl/nginx.key;

 ssl_dhparam /etc/nginx/ssl/dhparam.pem;

 ssl_session_timeout 5m;

 ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

 ssl_ciphers 'ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS';

 ssl_prefer_server_ciphers on;

 location / {

 client_max_body_size 100m;

 proxy_set_header X-Forwarded-Host $host;

 proxy_set_header X-Forwarded-Server $host;

 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

 proxy_pass http://127.0.0.1:9090;

 }

 location /synchrony {

 proxy_set_header X-Forwarded-Host $host;

 proxy_set_header X-Forwarded-Server $host;

 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

 proxy_pass http://127.0.0.1:9091/synchrony;

 proxy_http_version 1.1;

 proxy_set_header Upgrade $http_upgrade;

 proxy_set_header Connection "Upgrade";

 }

}

server {

 server_name paywiki

 listen 80;

 return 301 https://$server_name$request_uri;

}

It's work ok, but for some reason it shows

while trying to edit any page.

I've already added paywiki:443 as proxyName and proxyPort, and have changed scheme to https

<Connector port="8090"

               maxThreads="48"

               minSpareThreads="10"

               connectionTimeout="20000"

               enableLookups="false"

               protocol="org.apache.coyote.http11.Http11NioProtocol"

               redirectPort="8443"

               acceptCount="10"

               debug="0"

               URIEncoding="UTF-8"

               secure="false"

               scheme="https"

               proxyName="paywiki"

               proxyPort="443"

               maxHttpHeaderSize="8192" />

 Also I've already changed base_url from http://paywiki:8090 to https://paywiki but still get the same error.

POST requests like:

https://paywiki/synchrony/v1/data/Synchrony-4f4f4474-dcbd-3f22-a66c-9fdac33df0bf/confluence-4587669

are returning 500 error with java.lang.ClassCastException error message from atlassian-synchrony.log:

Where should I search for th type error?