i cannot install lightroom 6. I received a message after I received the serial number that stated "the signature of download_Adobe_Photoshop_Lightroom_6_ (Windows) exe is corrupt

delete that file and redownload.

repeated problems with that can be avoided by using a different browser and/or a different wired connection and/or a download manager and/or downloading from prodesigntools.com

if you follow all 7 steps you can directly download a trial here:  New Adobe Lightroom 6 (CC) Direct Download Links – Free Trials | ProDesignTools

and use your serial number to activate to the full non-time-limited version.

if you have a problem starting the download, you didn't follow all 7 steps, or your browser does not accept cookies. 

the most common problem is caused by failing to meticulously follow steps 1,2 and/or 3 (which adds a cookie to your system enabling you to download the correct version from adobe.com). 

failure to obtain that cookie results in an error page being displayed after clicking a link on prodesigntools.com or initiates the download of an incorrect (eg, current) version.