When you update, in case the error message “The installation of the application can’t be comfirmed” appears, it means that installation information of the Piapro Studio is broken or Piapro Studio doesn’t install.
After you reinstall the Piapro Studio, try updating again.

There are two types of the updata of the Piapro Studio, one for stand alone version and another for VST version.
When you use the Piapro Studio for the VST version, check whether you don’t download the updata for the stand alone version.

Check here for more information about the way to update.