I've been practicing updating Indy on a VM and I've gotten far enough to compile some of my projects but not all.
First of all I'm Delphi Seattle, updated to Indy 10.6.2 following the instructions here
In my client projects that use Indy, there is IPPeerClient in the Uses clause. This is causing the error "Unit IPPeerClient was compiled with a different version of IdTCPConnection.TidTCPConnection". I can remove the Use statement and they seem to be working (so far, the ones I've tested).
But for my server projects (datasnap and others), if I try to remove IPPeerServer, it gets added back in automatically and I'm stuck.