@kittyloo
Maybe this information will help that I found online at Medelita blog.
Since the early 1990s until August 2007, Sanita® manufactured all of the Dansko® stapled clogs collection, including Dansko® Professional Clogs. In August of 2007, Dansko® and Sanita® ended their long-term partnership. Dansko® began their own manufacturing in China, and Sanita® decided to continue their Professional Clog line under their own name, with continuation of production in Europe.
Since Sanita® stopped manufacturing Dansko® Professional Clogs, Dansko® has experienced some inconsistencies with their clogs - most noticeably, many of our customers have commented that the new heel design and higher arch on Dankso clogs is uncomfortable, causing ankle instability in a fast-paced, on-your-feet-all-day work environment. In short, if you want the same Dansko® clog that you loved prior to 2008, then you should buy Sanita®.
I also read there are other brands (like Born and Clarks) that also use the same molded polyurethane so have also crumbled after being shipped to customers.
If you Google Dansko Crumbling you will find others with the same issues plus pics are posted.