The download did not finish and the install failed. My update history lists the installer as installed; it wasn't. From now on I will do proprietary software downloads and installs at home. My home computer had no problem with the Flashplugin installer download and install and it's a slower computer. My Internet service is a lot faster than the one at the Coffee Shop and it's steadier, too. Can I get a second shot at the Adobe Flashplugin installer download?
You could try to uninstall it and reinstall, either in Software Center or by command line:
Although the other poster is correct and you can remove and reinstall the package, you could instead download the gzip file from URLs a bit like e.g: http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_126.96.36.1998.orig.tar.gz (the URL will change depending on your architecture and Flash version: check the directory index to be sure you've got the right one.)
With a gzipfile already available, you can simply reconfigure the package using:
This puts you into interactive mode, where you can specify the location of the downloaded gzipfile.
Reconfiguring is technically the right way to do it, especially if other packages depend on