Digital signature is invalid or missing.

      NOTICE: SketchUp 2015 is here! When you look at this Knowledge Center article, be sure to pick "SketchUp 2015" from the red box above to see the 2015 version of that content. If there is no version picker, this content applies to all versions of SketchUp.

SketchUp has a digital signature imprint from Verisign, so if you receive a message that there is an invalid digital signature or no digital signature, the likely cause is that installation file was corrupted during download.

In that case, clear your browser's cache, and then try the download again. Note: It can take up to 30 minutes to clear the cache.