When publishing, there is just generic errors. It should be specific to the file if that's possible.

Otherwise someone would have to go through each file individually to figure out which is the culprit. (time consuming, especially if there are many resources)

Example:

[XrmToolkit v5.1.0.0] -- <Error> -- 07/09/2017 1:56:19 PM -- Errors were encountered during the publish process:

Errors:
Unable to update the file in CRM: Object reference not set to an instance of an object.
Unable to update the file in CRM: Object reference not set to an instance of an object.
Unable to update the file in CRM: Object reference not set to an instance of an object.
Unable to update the file in CRM: Object reference not set to an instance of an object.
Unable to update the file in CRM: Object reference not set to an instance of an object.
Unable to update the file in CRM: Object reference not set to an instance of an object.