RH8 Can't open topics

I cannot open my topics when I do any of the following:

• double-click on a topic
• click the pencil icon
• righ-click and select "Edit Topic"

The only way I have found to open my topics is to right-click from the topic in the Topic List and select: Edit with > Design View

I am working with RH8 on a local drive.

The same problem happens with all projects on this computer.

On another computer, it works fine.

Thanks in advance,

Debbie