Follow the below steps to change Encoding so that user can .PSA files to open in older versions which was created in 2017.1:
1. Open .PSA File in Space Planning (2017.1 version)
2. Click on "File" Menu
3. Click Save>>Save As option
4. A warning message might appear, Click on "Save anyway" (Clear warnings if required or correct the warning)
5. A window will appear to save the project ,the default Encoding is Unicode UTF-8 (Which is not supported by older versions), change the "Encoding" to "ANSI" and click "Save"
