Service publishing issues when reusing MXDs
I want to understand better why we are having publishing issues when trying to reuse MXDs. The errors are not consistent, however, we seem to not get the errors at all when very precise steps are followed. I'd like to find a way to better stage publishing tasks for our team or, at the very least, have a better answer for why these errors are happening. Right now, my best answer is either just saying "999999" or "segmentation violation". 
Software / Hardware:
- 3 GIS server environments - Dev, Test, Prod - in version 10.4.1 / Windows Server 2012 R2 (each environment is load balancing with 2 web adapters, 2 GIS servers, and 1 file share)
- ArcGIS Desktop version 10.4.1 / Windows 10 and Windows 7
- Windows authentication is used for logins
Process that works:
- New (or resaved with new name for republishing/updating service) MXD
- Publish service (Dev parameters/capabilities/etc are set up from scratch and Test/Prod import the settings from Dev services)
We noticed that if we do not follow the steps above for each service, the follow errors MAY appear. These seem to occur with some projects more consistently than others.:
- Error: Packaging succeeded, but publishing failed. ERROR: unable to connect to publishing tools serv... (The only thing that makes sense in our case is the web-tier authentication)
- Sometimes resaving the MXD is not enough and instead of using the import feature in Service Editor, I have to recreate the settings by scratch instead of using a "template"
- Sometimes, the Export Map operation will return an imageData format instead of href format (JSON). (similar issue described here with workaround we are using)
I attempted to use service definition (SD) files but abandoned because I couldn't tell if they were adding to the issues or not. It is my gut feeling that the issues stem more from the reuse of MXDs for republishing/updating. Can anyone confirm this?
With all the above said, if we are required to resave MXDs in order to avoid these errors, why does this happen? Is there anything we should be doing to prevent resaves as being a requirement for successful publishing?
Many thanks in advance!
