XML-Sitemap functions broke on version 1.7.3

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Navigating to “SEO” –> “XML-Sitempas”
There appears:
Activate functions for XML Sitemaps.
Your Sitemap can be found here: (XML Sitemap) [Button]

Clicking on the button it opens the page:
https://www.alle-schweizer-wettbewerbe.ch/sitemap_index.xml
or more generic:
https://www.mydomain.ch/sitemap_index.xml

Before the release I could see some information and the different sitemaps as links such as:
category-sitemap.xml
post-sitemap.xml
post_tag-sitemap1.xml
post_tag-sitemap2.xml
post_tag-sitemap3.xml

Now, after the release 1.7.3, I receive a page error when clicking the button: Your Sitemap can be found here: (XML Sitemap) [Button]

I have the same problem.
Version 1.7.1 on WP 4.1

category-sitemap.xml
post_tag-sitemap.xml

gave me a 404 page

page-sitemap.xml Google wont find sitemap, but tell there is an error

For those that had an issue with the SEO 1.7.3 update, where after updating the in-app link to the XML Sitemap was returning a 404 error, which was confirmed by Google Webmaster, note the following in my case, which fixed the problem for me. I had two other plugins that I updated at the same time, one of which was the latest WooCommerce plugin. I deactivated then reactivated both of the other plugins after which the SEO plugin worked properly and the XML Sitemap was no longer returning a 404 error. I hope this helps.

thegrape.com
WordPress v4.1
WooCommerce v2.3.4
Legenda theme v2.5 by 8 Themes

Just installed WordPress SEO by Yoast release 1.7.3.1 and this fixed the issue! Thanks!