Desta:

If I understand your question it appears as if you are missing either your Sage 50 data file or your Sage 50 starter file. In order to open your data in Sage you need to have both. The .sai file is the starter file and the .saj file/folder is the data file. You must have these 2 files/folder in the same folder stored on your computer's hard drive in order to open the data. Once you find the required files/folder you can double click on the .sai file to start the opening process of Sage 50.