This KB article describes how to troubleshoot the issue when the Send to Proof Server task fails with the following error:
"Error message: CancellingJob has errors!".
More information about the reason why the job is cancelled is not available. Even in the Proof Client, there is no indication because the job is removed from the queue. You have to consult the proof server to find out what goes wrong:
You can conclude that something goes wrong when sending the data to the proofer.
If the jobs only fails when the Verification option is enabled then it's related to the SpectroProofer! In this case you should use Epson software to verify if the issue also occurs without using Esko Software.
This procedure describes how to use Epson software in order to prove that it's an Epson/ hardware issue:
Install the Windows driver if not available (In the Epson website go to Support > Drivers & Software > Drivers).
Click Preparing and executing a color measurement job.
Select Printing and color measurement of the color chart and click the Next button.
Select the correct paper in the Media Type drop-down list and select as well the correct Source and Size.
Select the same Media Type which you selected on the Proofer panel when loading the paper!
Click the Next button.
Select LEVEL 1 in Quality and click the Next button.
Click No when asked to run the Printer Linearization.
Now click the Execute button.
Evaluate the status.
Here is an example of a failing SpectroProofer:
It's not clear what goes wrong but this shows clearly that the issue is not on the Esko side. If a reboot of the proofer and a reinstallation of the SpectroProofer doesn't help then Epson support must be involved.