Why is this an issue?

Delphi code should not be indented with tab characters. Doing so has a number of detriments:

• Developers must configure the tab width of their text editors
• Spaces and tabs may be mixed in code
• The resultant code violates Delphi's Object Pascal Style Guide

How to fix it

Instead of using tab characters, indent two spaces for all indentation levels.

type
  TMyObject = class(TObject)
  public
    procedure Foo;
  end;

Resources

• Delphi's Object Pascal Style Guide: White Space Usage