I have many existing RTF files that load but do not display correctly in TAdvRichEditor using the TAdvRichEditorRTFIO.Load() function. These files load and display correctly in a TRichEdit component, WordPad (Windows 10), and Word. I also tried to copy from WordPad and paste into the TAdvRichEditor control with the same results.
Here is the contents of a sample RTF file that does not display correctly:
{\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang1033\deflangfe1033{\fonttbl{\f0\fswiss\fprq2\fcharset0 Arial;}{\f1\froman\fprq2\fcharset0 Times New Roman;}{\f2\froman\fprq2\fcharset2 Symbol;}{\f3\fnil\fcharset0 Calibri;}}
{\stylesheet{ Normal;}{\s1 heading 1;}{\s2 heading 2;}}
{*\generator Riched20 10.0.19041}\viewkind4\uc1
\pard\s1\sb240\sl252\slmult1\ul\b\f0\fs32 100\f1\par
\pard\keep\keepn\s2\fi-360\li720\sb240\sl252\slmult1\ulnone\b0\f2'b7\tab\f0 This is 1.\f1\par
\f2'b7\tab\f0 This is 1 & 2. \par
\pard\s1\sb240\sl252\slmult1\ul\b 110\f1\par
\pard\sa200\sl276\slmult1\ulnone\b0\f3\fs22\lang9\par
}