Unable to change Hosting type status for a domain in Plesk: Default FTP Server isn't specified at (FtpServerManager::get_adapter line 351)

Symptoms

• Unable to change Hosting type status for a domain in Domains > example.com > Hosting Settings or Plesk > Tools & Settings > FTP Settings:
  

  PLESK_ERROR: Error: ftpmng failed: Default FTP Server isn't specified at (FtpServerManager::get_adapter line 351) at get_adapter(FtpServerManager::get_adapter line 366) at execute console command --add-ip-address(vconsoleapp::start line 93) at execute "C:\Program Files (x86)\Plesk\admin\bin64\ftpmng" --add-ip-address "--ip-address=203.0.113.2"(vconsoleapp::run line 110) (Error code 1)

• The Microsoft FTP Service can not be found in Plesk > Tools & Settings > Services Management. 

Cause

Misconfiguration in Plesk Server Components

Resolution

1. Log into Plesk
2. Go Tools & Settings > Server Components and click Refresh button