This is a duplicate of #1069 broken rendering in tt-rss feeds, which seems to affect 1.8.12 and 1.10-RC1
Many feeds display an error:
"This page contains the following errors:
error on line 39 at column 271: Opening and ending tag mismatch: br line 0 and html"
-Affects some feeds, not others.
-Affects 100% of items in affected feeds.
-Affected feeds from various sources.
-Affected feeds originate from the same sources as unaffected feeds.