When adding an FTP account it is working for a while then fails with the error Bad Gateway. No specific error could be found in log files.
HTTP servers is waiting till
ftpmng.exe backend utility finishes working on the IIS service node. If the virtual host directory contains a lot of files (~100K) or has big size, it may take a couple of minutes to apply NTFS permissions which overages timeout value for Apache on Management Node.
The behavior was considered as internal software issue with id PPA-2363 and will be fixed in future PA updates.
To resolve the issue perform following steps:
Open Apache configuration file on Plesk Automation Management node:
# vi /etc/httpd/conf/httpd.conf
600, save file
# service httpd reload