Cannot Download from PC to Device in ProSoft Configuration Builder

When changing the IP address of a Modbus TCP module, the "Download from PC to Device" option can be grayed out if there are Modbus Master commands with IP addresses that still reference the old IP Address subnet. In this case the configuration is assumed invalid due to the fact that the commands still reference the old subnet. Update the Master commands, and the "Download from PC to Device" option will become available again, once the configuration has passed validation by ProSoft Configuration Builder.

Note: This behavior is not noticed if the option to "Disable Range Checking Functionality" under Tools->Options, is CHECKED, which is not recommended by ProSoft Technical Support.