Field Maps unable to open MMPK

Question

Hello, I am trying to create a large .mmpk ~10GB for use with Field Maps. Since the file is so large and takes so long to process I've been adding a few layers and processing a new mmpk to test. Every iteration has worked until yesterday when I added my final layers. Now I am getting an error that reads, "Unable to Open Map. An error occurred opening the map. URL must not be null or empty." How do I get past/fix this so I can open the mmpk? 
I've removed the recently added layers to get back to the last version that works and reprocessed the package but am now still getting the same error. I am sideloading the .mmpk on to the device. Thanks in advance for any advice!

Anonymous User · Answer

@AndyJens

I have not ran into this myself so I can't say for sure, but moving the layers into a new map in a new project like you suggested may very well fix the problem. If you can send me a clipped version of the map I can try to reproduce and / or come up with a workaround in case moving to a new project does not solve the problem. Please email me at jwhitney@esri.com and I can provide you a location to upload the clipped MMPK.

Joel

AndyJens · Answer

Hey @Anonymous User thanks so much for your reply! I did have a version that reference online services, but it threw an error pretty quickly telling me that I couldn't use that data type. I removed those layers so that the current version only references data on my C: drive. If there's a bug in the Create Mobile Map Package tool will that likely only exist in that project? I.e., if I group all my layers, save it as a layer file, and then move it over into a new project do you think that will fix the issue? I can also try to share a clipped version to see if you're able to replicate the issue, what's the best way to do that?

Anonymous User · Answer

Hey @AndyJens,

Does this MMPK reference online layers? Did one of the versions of the map you create have online layers? It sounds like the app is expecting one of the layers to have an online source when the URL field is likely empty. This may be the result of a bug in the Create Mobile Map Package tool bug that somehow resulted in the MMPK getting corrupted. Are you able to share a clipped version of the MMPK? There may be an easy fix if I can reproduce it on my end.

Joel