Hi,
When an error "could not write file, load will not complete" is issued it typically indicates that there is a problem with the driver or the target. Do you have more than one custom board you can test to see if the behaviour is the same on all of them?
It also may be worth ensuring there is no write-protect enabled on your target flash part.
If you would like us to take a look at your driver, please provide the complete project. If you prefer to do so through private support, please use the link below.
The '-verbose' switch offers the most detail you will get from the CLDP during execution.
Regards,
Craig.