SmartCrawl is returning a blank page on sitemap

I’m having issues creating the sitemap with SmartCrawl. If all the plugins are active on the site, returns:

500 Internal Server Error


If leaving only SmartCrawl and the WPMU DEV Dashboard active on it, the sitemap returns a blank page and there is an error on the console log, but on the sources section the sitemap is available.

I noticed that the issue seems to be related to SmartCrawl not processing properly the sitemap. For rome reason it is created it on http instead of https. If typing directly on the browser, the sitemap is properly displayed, but the sitemap button under SmartCrawl > Sitemap page is pointing to, which returns the error.