This error is indicative of a backplane issue between the prosoft card and the compact logix PLC.
With the MVI69E and MVI69L modbus modules, all of the configuration is stored on the PLC itself, not on the Prosoft card. This means that, unlike with some of our other modules, it is possible to perform a download while our card does not have a backplane connection to the PLC and have the download be successful. However, in order to actually get the new configuration into the module, a reboot notice must then be sent from the PLC to the card, as the card will load whatever configuration the PLC has on boot up. If we don't have a backplane connection, this will result in the "download was sucessful but module failed to reboot" error.
Common causes include:
1) Your Compact Logix is not in run mode.
2) Your Prosoft card's Add-On Instruction is either not installed, or the rung it is on is not being completed, scheduled, or jumped to.
3) You have not yet installed the right end cap.
4) There are more then 3 cards separating the Prosoft card and the nearest power supply.
5) Your Prosoft card's Add-On Instruction block is not aiming at the correct slot (for example, it's connection input is set to local:1:I:Data when we the card is located in slot 2).
6) You have a destructive rung of ladder (such as a copy, move, etc.) besides Prosoft's AOI putting data into the card's Local Controller Tag (for example, you are attempting to copy data directly to the cards associated local tag instead of to its WriteData tag array created by the Add-On Instruction Rung).
If none of these issues appear to be the cause of the error, please contact you're Tech Support department for your region for further assistance: http://www.prosoft-technology.com/SERVICES-SUPPORT/Customer-Support