I downloaded a project from a CPU 1214C, 6ES72141HG400XB0.

I used TIA v18 to pull the program off the plc because I did not know what version it used.

The program was v15.1 so I couldn't open it in v18, but was able to save it.

I now have v15.1, but cannot open the project. It doesn't even give the option to open. I notice that the project file type is Siemens TIA Portal V18 project (.ap18). When opened in v18 it looks empty.

Is there a way to open the project in the correct version 15.1 even though I saved it with v18?

Hi Landon1220,

In this case, I would recommend that you review the following FAQ that I share below since it explains in detail the options that exist to perform an upload:

"What options are available in STEP 7 (TIA Portal) for uploading when the project version on the CPU no longer matches the version on your PG/PC?"

On the other hand, in principle when you connect online with the PLC it usually tells you the version with which the project was loaded.

Best regards!