Heads up, looks like 100.8 has introduced a new MMPK problem, centered around GetLegendInfosAsync. As soon as I can isolate the problem and set up a working example, I'll get it off to tech support. Has anyone else seen this yet?
"Cannot call this method in this context: Object failed to load, unable to execute task."
This is only happening with a particular MMPK and not the others I work with, so I wouldn't be surprised if it's a symbology issue.