Because Vegas Pro 13 is an older product, its original Sony activation servers are sometimes offline or have moved. Ensure you have the installed. Later builds were updated to point toward the correct MAGIX authentication servers. "Invalid Serial Number"
This usually starts with "1TR" and is used to identify your specific license. sony vegas pro 13 authentication code
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Sony Creative Software\Vegas Pro\13.0\License Because Vegas Pro 13 is an older product,