HI Bill, (1) are you using the debug library? if so, then try without. (2) an asset error means you've hit a condition that the Tableau developers didn't expect. If you can come up with a reproducible test case, contact Support and let them know. (You can also report this without a repro, but if you can't repro it, then Tableau may not be able to find the problem.)
I was using tableau-2.js. I switched to tableau-2.min.js, and so far, after about 4 hours, it is still running without the error. Thanks so much!
Did you try it without Debug library, Is that worked for you??
Let me know how you encountered this issue and what steps you took in tableau to resolve it