Last version form LTS 1.9.4.x and php 7.2.30.
We've encountered the issue when we tried to use "Flush Magento Cache" from backend. The error occurs in our logs as a warning and we are not sure how to solve this.
Logged Error Warning: SimpleXMLElement::__construct(): Entity: line 6: parser error : Opening and ending tag mismatch: hr line 5 and body in /***/Mage/AdminNotification/Model/Feed.php on line 172
Logged Error Warning: SimpleXMLElement::__construct(): </body> in /***/Mage/AdminNotification/Model/Feed.php on line 172
Logged Error Warning: SimpleXMLElement::__construct(): ^ in /***/Mage/AdminNotification/Model/Feed.php on line 172
Logged Error Warning: SimpleXMLElement::__construct(): Entity: line 7: parser error : Opening and ending tag mismatch: body line 3 and html in /***/Mage/AdminNotification/Model/Feed.php on line 172
Logged Error Warning: SimpleXMLElement::__construct(): Entity: line 7: parser error : Premature end of data in tag html line 1 in /***/Mage/AdminNotification/Model/Feed.php on line 172
the data returned by url is
<html>
<head><title>301 Moved Permanently</title></head>
<body>
<center><h1>301 Moved Permanently</h1></center>
<hr><center>nginx</center>
</body>
</html>
the called url is: ‌https://openmage.github.io/Web_Notifications/notifications_v1.rss
which redirects to http version:
HTTP/2 301
server: GitHub.com
content-type: text/html
location: http://www.openmage.org/Web_Notifications/notifications_v1.rss
Thank you @tmotyl.
Based on your response, the solution in our case is to copy the core file "../AdminNotification/etc/config.xml" to local and remove the feed url.
@Flyingmana Any reason not to enable Enforce HTTPS?

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@Flyingmana Any reason not to enable Enforce HTTPS?
