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.
Best Answer
I Have QGIS 2.14.13 and OpenLayers Plugin 1.4.3 installed and here the Plugin works just fine.
However their is another Plugin for WMS Layers called QuickMapServices. This plugin also works fine when Printing the map, which OpenLayers Plugin does not.