THE INFORMATION IN THIS ARTICLE APPLIES TO:
The new SFTP library is not allowing connections to a remote server using "diffie-hellman-group-exchange-sha256" and “diffie-hellman-group-exchange-sha1“ KEXes.
Create the following registry setting:
HKEY_LOCAL_MACHINE\Software\WOW6432Node\GlobalSCAPE Inc.\EFT Server 7.4\
Value name: SFTPEnableGroupsExchangeKex
Default Value: 0 (disables both ciphers, "diffie-hellman-group-exchange-sha256" and “diffie-hellman-group-exchange-sha1“)
See also https://kb.globalscape.com/KnowledgebaseArticle11439.aspx