For other problems (inlcuding error messages like "such-and-such is not a Director file") first clear your browser cache.  If you need help doing that, check this page.  If your browser isn't listed there then click on its Help menu and search for the instructions you need.

If clearing your cache doesn't solve the problem, then close your browser and restart it.  You may need to restart your computer, too.

If you're still having problems after doing all those things then your Shockwave files may be corrupt.  You can troubleshoot Shockwave problems here.   If you need to reinstall Shockwave, please remember you must first use their uninstall program (choose the Windows or Mac version) to remove your old files.  Simply deleting the files or writing over them will not fix problems.