When you try to insert a placeholder in a Word document, you receive the following error message: Call was rejected by callee. (Exception from HRESULT: 0x80010001 (RPC_E_CALL_REJECTED))
According to the Microsoft Knowledge Base, this error can occur if a certain option is not activated. In order for communication with Word to function, the option Show all windows in the taskbar
has to be enabled. See the original article
We unfortunately could not reproduce the error on our PCs by deactivating this option. In any event, it’s much more likely that an overzealous anti-virus program is blocking access to Word and causing the error to occur. If you use anti-virus software, please deactivate it temporarily to see if the error still occurs.