characters shows as “?”

1. Compile the  struct samples in FDK11

2.Open with “Framemaker11”

3.Insert characters as below in FM11

4.Some of characters shows as “?” （eg：）。 Also ，after save and close， reopen it，some of the characters shows as “?” too.

Please help me solve the problem, so that we will not show “?” after reopen it.