Can't Add MSI to Software in GPO
Software Installation was unable to read the MSI file TheMSIname.msi. The following error was encountered: No more data is available.
Coming to the Solution
Used ORCA to Validate the package. In the logs, there were many WARNINGS, but the first Error showed that PropertyVersion in the MSI was missing. This is fatal. Added the PropertyVersion in the Property section and saved the file. Voila!