The dreaded "Error: Last attempt to publish to the MDEX Engine failed at" error.
In our project, we are using the IFCR export/import node to move content pages from dev->qa->prod and we see this error a bunch.
I don't assume this is something you are doing, however, the main reason why I am posting to this thread is to see if anyone knows where, if anywhere, the application logs the specific error message? I have searched through the workbench logs to no avail.
To add information for others that may be merging content data and migrating it, here are the few issues we have noticed.
1) Be aware that each environment keeps it's own sequence of merch rule ID's (each content group entity has an individual ID), and in the case of importing to another environment and modifying the template, there is a potential for ID collision. If this happens, you will get the publishing error. (Oracle known issue).
2) If you do not keep consistent dim value ID's (example: autogen per environment), and a template is using a dim value in the location is does not know, you will see this error.
3) If you are using other cartridge types that pull in dim val data, and the value does not exist in the environment you are publishing, you will see this error.
I hope that I am just overlooking the lack of logging in this case, cause this is a real troublesome issue.
If this is related to the dim val ids that are used as triggers being inconsistent across environments, then Oracle has a patch for this (6.4.0 and 6.4.1). Describe this issue to them in a ticket and they will direct you to it.
We deployed this patch over a month ago and no longer see the dreaded "Error: Last attempt failed!!!!!"