Currently distributed windows build on website is annoyingly pedantic about format for TMS paths/servers, or generates NO imagery for given entry.

[afarlie]

ALL of the Imagery sources in the following TMS servers file exist ( because I've been able to see them in a Web Browser.) Only the Mapnik layer loads reliably in Merkattor

<?xml version="1.0"?>
<MerkaartorList>
 <TmsServers creator="Merkaartor v0.18.3">
  <TmsServer minzoom="0" maxzoom="0" deleted="true" path="/layer/gb_os_sv_2016_04/%1/%2/%3.png" tilesize="0" name="New Server" address="https://b.os.openstreetmap.org" projection="EPSG:900913"/>
  <TmsServer minzoom="0" maxzoom="0" path="/os1/%1/%2/%3.jpg" tilesize="0" name="OS (1:25000)" address="https://a.ooc.openstreetmap.org" projection="EPSG:900913"/>
  <TmsServer minzoom="0" maxzoom="17" path="/%1/%2/%3.png" tilesize="256" name="OSM.org Mapnik" address="http://tile.openstreetmap.org" projection="EPSG:900913"/>
  <TmsServer minzoom="0" maxzoom="17" path="/%1/%2/%3.png" tilesize="256" name="OSM.org Mapnik Test" address="http://tile.openstreetmap.org" projection="EPSG:900913"/>
  <TmsServer minzoom="0" maxzoom="0" path="/maps/tiles/qi46/%1/%2/%3.jpg" tilesize="0" name="SABRE (QI-1946)" address="https://www.sabre-roads.org.uk" projection="EPSG:900913"/>
 </TmsServers>
</MerkaartorList>

[Krakonos]

Hi! The problem is with the layer settings, as you have maxzoom=0 and tilesize=0. I tried modifying those to maxzoom=17 and tilesize=256 and all of those sources work just fine. The first one also has deleted=yes, which should not be there for it to work.

When modifying, keep in mind the bug #88 .

I will modify the TMS dialog to preset those values by default, as it might be hard to guess them.