I just fixed an issue with the Restore-PfaProtectionGroupVolumeSnapshots cmdlet or alias restorepgsnap. This cmdlet supports restoring volume snapshots from source and target protection groups that I originally posted in the following article, http://www.themicrosoftdude.com/?p=3801.
The details of the problem are documented in Issue #6 (https://github.com/purestorage/PowerShell-Toolkit/issues/6).
The fixes are available in v188.8.131.520
v184.108.40.2061, download from https://github.com/barkz/PureStoragePowerShellToolkit/blob/master/PureStoragePowerShell_2_8_0_430.msi https://github.com/purestorage/PowerShell-Toolkit/blob/master/PureStoragePowerShell_2_4_2_311.msi. I suggest uninstalling the previous version from Program and Features then installing the new version.