Opening existing project in Delphi 10.2 reports error that "Class TBarSeries not found."

This is a strange one, and is related to the Delphi IDE environment, but I'm hoping someone has some insight, cos I'm at a loss.

Basically, the problem is that I'm now in a situation where any project I create that uses a TChart with a TBarSeries gives me the "Class TBarServices not found" error when I re-open it from a fresh start of the IDE.

As an example, currently if I do the following:

• Create a new VCL forms application,
• add a TChart component to the form,
• edit the chart through the designer and add a Series, choosing Bar as the type.
• Build the project,
• run it, everything is fine.
• Close the IDE and restart it.
• Open the previously saved project. Immediately get the Error Reading Form message about Class TBarSeries not found.

But if I then:

• Close the broken project without saving, and leave the IDE running.
• Create a new VCL form with or without a project,
• add the TChart and bar Series to the form,
• close the form/application without saving.
• Reopen the previously saved project that threw the error. No error any more.

Creating a new TForm with a TChart and TBarSeries is changing the Delphi IDE in some way that is not persistent, so that the next time the IDE is started, those projects no longer load properly.

I have included VCLTee in the Unit Scope Names, but the Enterprise version of Delphi 10.2 does not include the source for these components, so there are no additional paths I can add to the Library Path.

Once I have created a new form and set up the chart, everything is fine with any project that uses the TBarSeries so long as I don't close the IDE, so that's the workaround I currently employ.

Do you use DevExpress? I had the same problem when DevExpress Printing System for DBTeeChart was installed. Probably DevExpress uses old version of TeeChart different than this installed by you. I just disabled this DevExpress Printing System and now it's OK.