I've found the answer. I had just copied the project sources from the XE5 folder to the XE10 folder.
I needed to then delete the XE10 .dproj files as they still point to the XE5 folders/components.
Might be worth keeping this as others may do the same.

Hello I have just set up a new machine with Delphi XE5 and XE10.4 Sydney. I have applied all patches. I have installed TeeChartVCLFMXSOURCE-2020.30.exe and compiled everything for both versions. XE5 is running fine, but when compiling a copy of the same code in XE10.4 Sydney I get the error: VCLTee....

I'm trying to add functionality to allow users to reorder charts on a dashboard and save their positions in the underlying database. I've tried using the OnDragDrop and OnEndDock events on TDashboard, but they don't seem to fire, so I'm guessing that the events are on the charts themselves? Could yo...