the QGIS OpenLayers Plugin version 1.4.3 shows all OSM WMS Layers broken with black- or redscreen "tiles". A colleaque had version 1.3.6 installed and it worked fine. I was already on 1.4.3 with broken layers. With the new version (1.4.2?) OSM layers was split up in two groups (OpenStreetMap, OSM/Thunderforest). After updating to 1.4.3 my colleaques OSM layers were also broken. We both use QGIS 2.18.0 on Windows7-64bit machines.
I searched Google, the Github-Repository and StackExchange but I can't find a bug report on this issue.