diff --git a/src/map/IMG/rastertile.cpp b/src/map/IMG/rastertile.cpp
index dd4c5b20..5476f880 100644
--- a/src/map/IMG/rastertile.cpp
+++ b/src/map/IMG/rastertile.cpp
@@ -445,7 +445,11 @@ void RasterTile::fetchData(QList<MapData::Poly> &polygons,
 
 	if (dynamic_cast<IMGData*>(_data)) {
 		_file = new QFile(_data->fileName());
-		_file->open(QIODevice::ReadOnly | QIODevice::Unbuffered);
+		if (!_file->open(QIODevice::ReadOnly | QIODevice::Unbuffered)) {
+			qWarning("%s: %s", qPrintable(_file->fileName()),
+			  qPrintable(_file->errorString()));
+			return;
+		}
 	}
 
 	QRectF polyRect(ttl, QPointF(ttl.x() + _rect.width(), ttl.y()
diff --git a/src/map/IMG/subfile.h b/src/map/IMG/subfile.h
index 8d76396a..762a6ecc 100644
--- a/src/map/IMG/subfile.h
+++ b/src/map/IMG/subfile.h
@@ -26,7 +26,9 @@ public:
 
 			if (!_file) {
 				_file = new QFile(subFile->fileName());
-				_file->open(QIODevice::ReadOnly | QIODevice::Unbuffered);
+				if (!_file->open(QIODevice::ReadOnly | QIODevice::Unbuffered))
+					qWarning("%s: %s", qPrintable(_file->fileName()),
+					  qPrintable(_file->errorString()));
 				_delete = true;
 			}
 			_data.resize(subFile->blockSize());
diff --git a/src/map/aqmmap.cpp b/src/map/aqmmap.cpp
index bc00b658..e2052923 100644
--- a/src/map/aqmmap.cpp
+++ b/src/map/aqmmap.cpp
@@ -258,7 +258,9 @@ void AQMMap::load(const Projection &in, const Projection &out,
 	Q_UNUSED(out);
 
 	_mapRatio = hidpi ? deviceRatio : 1.0;
-	_file.open(QIODevice::ReadOnly);
+	if (!_file.open(QIODevice::ReadOnly))
+		qWarning("%s: %s", qPrintable(_file.fileName()),
+		  qPrintable(_file.errorString()));
 }
 
 void AQMMap::unload()
diff --git a/src/map/conversion.cpp b/src/map/conversion.cpp
index c09bc643..5e441531 100644
--- a/src/map/conversion.cpp
+++ b/src/map/conversion.cpp
@@ -141,8 +141,7 @@ bool Conversion::loadList(const QString &path)
 	bool res;
 
 	if (!file.open(QFile::ReadOnly)) {
-		qWarning("Error opening projections file: %s: %s", qPrintable(path),
-		  qPrintable(file.errorString()));
+		qWarning("%s: %s", qPrintable(path), qPrintable(file.errorString()));
 		return false;
 	}
 
diff --git a/src/map/ellipsoid.cpp b/src/map/ellipsoid.cpp
index 97c30e4f..b5fa7c77 100644
--- a/src/map/ellipsoid.cpp
+++ b/src/map/ellipsoid.cpp
@@ -38,8 +38,7 @@ bool Ellipsoid::loadList(const QString &path)
 	bool res;
 
 	if (!file.open(QFile::ReadOnly)) {
-		qWarning("Error opening ellipsoids file: %s: %s", qPrintable(path),
-		  qPrintable(file.errorString()));
+		qWarning("%s: %s", qPrintable(path), qPrintable(file.errorString()));
 		return false;
 	}
 
diff --git a/src/map/gcs.cpp b/src/map/gcs.cpp
index 2aef8dcd..6593c4bc 100644
--- a/src/map/gcs.cpp
+++ b/src/map/gcs.cpp
@@ -102,8 +102,7 @@ bool GCS::loadList(const QString &path)
 	bool res;
 
 	if (!file.open(QFile::ReadOnly)) {
-		qWarning("Error opening GCS file: %s: %s", qPrintable(path),
-		  qPrintable(file.errorString()));
+		qWarning("%s: %s", qPrintable(path), qPrintable(file.errorString()));
 		return false;
 	}
 
diff --git a/src/map/gemfmap.cpp b/src/map/gemfmap.cpp
index 91797df3..1ad68d0b 100644
--- a/src/map/gemfmap.cpp
+++ b/src/map/gemfmap.cpp
@@ -189,7 +189,9 @@ void GEMFMap::load(const Projection &in, const Projection &out,
 	Q_UNUSED(out);
 
 	_mapRatio = hidpi ? deviceRatio : 1.0;
-	_file.open(QIODevice::ReadOnly);
+	if (!_file.open(QIODevice::ReadOnly))
+		qWarning("%s: %s", qPrintable(_file.fileName()),
+		  qPrintable(_file.errorString()));
 }
 
 void GEMFMap::unload()
diff --git a/src/map/jnxmap.cpp b/src/map/jnxmap.cpp
index 6cc72d70..bfad6f50 100644
--- a/src/map/jnxmap.cpp
+++ b/src/map/jnxmap.cpp
@@ -162,7 +162,10 @@ void JNXMap::load(const Projection &in, const Projection &out,
 	_projection = in;
 	_mapRatio = hidpi ? deviceRatio : 1.0;
 
-	if (_file.open(QIODevice::ReadOnly))
+	if (!_file.open(QIODevice::ReadOnly))
+		qWarning("%s: %s", qPrintable(_file.fileName()),
+		  qPrintable(_file.errorString()));
+	else
 		readTiles();
 }
 
diff --git a/src/map/mapsforge/mapdata.cpp b/src/map/mapsforge/mapdata.cpp
index 63e6ceb2..bae0e91a 100644
--- a/src/map/mapsforge/mapdata.cpp
+++ b/src/map/mapsforge/mapdata.cpp
@@ -459,7 +459,11 @@ RectC MapData::bounds() const
 void MapData::load()
 {
 	QFile file(_fileName);
-	if (file.open(QIODevice::ReadOnly | QIODevice::Unbuffered))
+
+	if (!file.open(QIODevice::ReadOnly | QIODevice::Unbuffered))
+		qWarning("%s: %s", qPrintable(file.fileName()),
+		  qPrintable(file.errorString()));
+	else
 		readSubFiles(file);
 }
 
diff --git a/src/map/mapsforge/rastertile.cpp b/src/map/mapsforge/rastertile.cpp
index 3aba51c8..ee42efa9 100644
--- a/src/map/mapsforge/rastertile.cpp
+++ b/src/map/mapsforge/rastertile.cpp
@@ -410,8 +410,11 @@ void RasterTile::fetchData(QList<MapData::Path> &paths,
 	QPoint ttl(_rect.topLeft());
 	QFile file(_data->fileName());
 
-	if (!file.open(QIODevice::ReadOnly | QIODevice::Unbuffered))
+	if (!file.open(QIODevice::ReadOnly | QIODevice::Unbuffered)) {
+		qWarning("%s: %s", qPrintable(file.fileName()),
+		  qPrintable(file.errorString()));
 		return;
+	}
 
 	QRectF pathRect(QPointF(ttl.x() - PATHS_EXTENT, ttl.y() - PATHS_EXTENT),
 	  QPointF(ttl.x() + _rect.width() + PATHS_EXTENT, ttl.y() + _rect.height()
diff --git a/src/map/pcs.cpp b/src/map/pcs.cpp
index c72c1dc5..bebe36ce 100644
--- a/src/map/pcs.cpp
+++ b/src/map/pcs.cpp
@@ -31,8 +31,7 @@ bool PCS::loadList(const QString &path)
 	bool res;
 
 	if (!file.open(QFile::ReadOnly)) {
-		qWarning("Error opening PCS file: %s: %s", qPrintable(path),
-		  qPrintable(file.errorString()));
+		qWarning("%s: %s", qPrintable(path), qPrintable(file.errorString()));
 		return false;
 	}
 
diff --git a/src/map/qctmap.cpp b/src/map/qctmap.cpp
index 6d05ef24..4373b1be 100644
--- a/src/map/qctmap.cpp
+++ b/src/map/qctmap.cpp
@@ -361,7 +361,9 @@ void QCTMap::load(const Projection &in, const Projection &out,
 	Q_UNUSED(out);
 
 	_mapRatio = hidpi ? deviceRatio : 1.0;
-	_file.open(QIODevice::ReadOnly);
+	if (!_file.open(QIODevice::ReadOnly))
+		qWarning("%s: %s", qPrintable(_file.fileName()),
+		  qPrintable(_file.errorString()));
 }
 
 void QCTMap::unload()
diff --git a/src/map/rmap.cpp b/src/map/rmap.cpp
index b107221c..ef1ac79f 100644
--- a/src/map/rmap.cpp
+++ b/src/map/rmap.cpp
@@ -365,7 +365,9 @@ void RMap::load(const Projection &in, const Projection &out, qreal deviceRatio,
 	Q_UNUSED(out);
 
 	_mapRatio = hidpi ? deviceRatio : 1.0;
-	_file.open(QIODevice::ReadOnly);
+	if (!_file.open(QIODevice::ReadOnly))
+		qWarning("%s: %s", qPrintable(_file.fileName()),
+		  qPrintable(_file.errorString()));
 }
 
 void RMap::unload()