CX Programmer read protection/unit version error

[Junado 1]

Good morning, I'm having an odd issue with CX Programmer and have hit a wall. I'm trying to upload a previous version of a program to an existing PLC (CS1G-H CPU42) and I keep getting the following error when I compile while online: "The read protection properties which are not supported by the connecting target PLC are set. Check the unit version of the PLC." This prevents the program from being uploaded. I have a first revision CS1, manufacture in 2005 from what I can tell. This exact program has been uploaded previously, but a modified version replaced it recently and I need to go back to the older version. Things I have tried so far. without success: - Removed UM Protection - Made sure Task protection is off for all tasks - Check DIP Switch #1, which is write protection, and made sure it is off - Used "Remove Password" and "Release access" functions from the PLC/Protection menu - Used the auto-verification to confirm the configured PLC is correct - Reuploaded a full backup of H & D memory, from the older program I am able to compile the program when offline, but it chokes when online. I am connecting to the PLC via a serial cable. I haven't found any help from the CX Programmer help, or the CS1 programming and operation manual. This error message is nowhere to be found. Anyone has a clue ? I'm at a loss right now. Thank you !

[Junado 1]

If anyone ever experiences this error, I have found a solution. Turns out my PLC was old enough (2003 actually) that it did not support the memory read/write protection on memory cards. I had to turn off the option in the properties window, protection tab, of the PLC in CX-Programmer. [edit: typo] Edited 31 Mar 2015 by Junado

[BITS N BYTES 66]

It's always nice to see that someone follows up by reporting the final resolution to their problem. Many members don't even bother but expect to be helped with their next challenge. Thanks - Junado