While initiating a chat session in the embedded Sametime client of Lotus Notes 8.0.1 I got the message “A Runtime Error has occured. Do you wish to debug? Line: 0 Error: Object expected”.
This also happened when another person started a chat with me.
The solution was to check the following options in Internet Explorer (Tools -> Internet Options -> Advanced):
Disable Script Debugging (Internet Explorer)
Disable Script Debugging (Other)
I also unchecked the option “Display a notification about every script error”.
After that the embedded Sametime client worked as expected again.