I am on version 4.3.1. I started a refresh of my cached sitemaps today after quite a while, probably the first time since I updated to 4.3.1 (holidays) and noticed an errormessage in the process:
-Parsererror- SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data
This happened upon clicking the button to refresh the sitemap cache. Also first clearing the cache and then regenerating it returned the same error. The caching process does not execute then.
See also the attached screenprint.