Once the fields are filled in the spinner comes up briefly then the page remains as is.. nothing happens
in the logs I get
2016/09/08 15:37:31 [error] 3668#3668: *3936179 FastCGI sent in stderr: "PHP message: PHP Fatal error: imagecreatefrompng(): gd-png: fatal libpng error: Read Error: truncated data
in /home/forge/xxxxxx.com/community/library/XenForo/Image/Gd.php on line 86" while reading response header from upstream, client: 255.255.255.255, server: xxxxxx.com, request: "POST /community/admin.php?forums/save HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php5.6-fpm.sock:", host: "xxxxxx.com", referrer: "http://xxxxxx.com/community/admin.php?nodes/insert"
GD appears to be correctly installed for both php 5.6 and php 7.o which are on the server.
It seems like a curious error as there don't seem to be any images involved it's simple the title and description field filled out with text.