OpenStreetMaps recently changed their server infrastructure to better handle the load. This had the side-affect of breaking all OSM-based maps in MyTrails because they now require a specific per-app User-Agent HTTP header.
Unfortunately MyTrails didn’t support directly editing the HTTP header so fixing the maps required updating the app.
The maps should be updated when you launch MyTrails after the update, unless you already changed an affected map, in which case MyTrails will create a fixed copy at the end of the list.
A change on the Minambiente site broke this map for MyTrails. Fortunately, a simple edit fixes it: MyTrails > Maps > tap on the IGM 25k (IT) line and in the map details editor, change the version from 1.1.1 to 1.3.0, then use the back button to save the change.
This will be available by default in the next beta release of MyTrails.
Update June 2019: the former IGM site disappeared entirely and I can’t find another source of high quality topo maps. I was able to find a server that offers black and white maps, but they’re broken down by region, so I can’t include them as-is in MyTrails.
Recently, the USGS maps in MyTrails haven’t been loading. This was a result of a server-side change on the map provider, and is fixed in the latest MyTrails 2.1 beta. Please upgrade to the beta to fix.
OpenCycleMap is operated by ThunderForest, a paid service. They overlay the message “API KEY REQUIRED” on their maps to encourage users to register with them.
You can create a free account and update the map definition in MyTrails > Maps > tap on the OpenCycleMap entry and edit the map URL, adding ?apikey=123abc at the end of the existing URL, where 123abc should be replaced with your real API Key.
The first part of the URL may also need to be changed from a.tile.opencyclemap.org
4UMaps are some of the nicer OpenStreetMap-based maps, maintained and served independently of OSM (and MyTrails).
They have recently updated their server, and some versions of Android seem to have trouble connecting to the new server. You can fix this by changing the map definition for 4Umaps to use the following URL:
Alternatively, just tap this link from your Android device to import a new map definition with this URL.