diff --git a/src/lang/english.txt b/src/lang/english.txt
index 75d9675891..ef2b19d0b9 100644
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -3779,4 +3779,6 @@ STR_CONTENT_ERROR_COULD_NOT_EXTRACT                             :{WHITE}Could no
 
 STR_CONTENT_INTRO_BUTTON                                        :{BLACK}Check online content
 STR_CONTENT_INTRO_BUTTON_TIP                                    :{BLACK}Check for new and updated content to download
+STR_CONTENT_INTRO_MISSING_BUTTON                                :{BLACK}Find missing content online
+STR_CONTENT_INTRO_MISSING_BUTTON_TIP                            :{BLACK}Check whether the missing content can be found online
 ########
diff --git a/src/network/network_content.cpp b/src/network/network_content.cpp
index bdb3608ed8..fa7f836247 100644
--- a/src/network/network_content.cpp
+++ b/src/network/network_content.cpp
@@ -218,7 +218,7 @@ void ClientNetworkContentSocketHandler::RequestContentList(ContentVector *cv, bo
 		ContentInfo *ci = *iter;
 		bool found = false;
 		for (ContentIterator iter2 = this->infos.Begin(); iter2 != this->infos.End(); iter2++) {
-			ContentInfo *ci2 = *iter;
+			ContentInfo *ci2 = *iter2;
 			if (ci->type == ci2->type && ci->unique_id == ci2->unique_id &&
 					(!send_md5sum || memcmp(ci->md5sum, ci2->md5sum, sizeof(ci->md5sum)) == 0)) {
 				found = true;
@@ -746,6 +746,13 @@ void ClientNetworkContentSocketHandler::CheckDependencyState(ContentInfo *ci)
 	}
 }
 
+void ClientNetworkContentSocketHandler::Clear()
+{
+	for (ContentIterator iter = this->infos.Begin(); iter != this->infos.End(); iter++) delete *iter;
+
+	this->infos.Clear();
+}
+
 /*** CALLBACK ***/
 
 void ClientNetworkContentSocketHandler::OnConnect(bool success)
diff --git a/src/network/network_content.h b/src/network/network_content.h
index ac169313f9..6e683dd7e5 100644
--- a/src/network/network_content.h
+++ b/src/network/network_content.h
@@ -117,6 +117,8 @@ public:
 	ConstContentIterator Get(uint32 index) const { return this->infos.Get(index); }
 	/** Get the end of the content inf iterator. */
 	ConstContentIterator End() const { return this->infos.End(); }
+	/** Clear all downloaded content information. */
+	void Clear();
 
 	/** Add a callback to this class */
 	void AddCallback(ContentCallback *cb) { this->callbacks.Include(cb); }
diff --git a/src/network/network_content_gui.cpp b/src/network/network_content_gui.cpp
index 398f838da6..2497c5a38a 100644
--- a/src/network/network_content_gui.cpp
+++ b/src/network/network_content_gui.cpp
@@ -684,6 +684,7 @@ static const WindowDesc _network_content_list_desc = {
 void ShowNetworkContentListWindow(ContentVector *cv, ContentType type)
 {
 #if defined(WITH_ZLIB)
+	_network_content_client.Clear();
 	if (cv == NULL) {
 		_network_content_client.RequestContentList(type);
 	} else {
diff --git a/src/newgrf_gui.cpp b/src/newgrf_gui.cpp
index d18ef00b6b..3596f52ec9 100644
--- a/src/newgrf_gui.cpp
+++ b/src/newgrf_gui.cpp
@@ -399,6 +399,18 @@ struct NewGRFWindow : public Window {
 			this->widget[SNGRFS_PRESET_LIST].data = STR_JUST_RAW_STRING;
 		}
 
+		bool has_missing = false;
+		for (const GRFConfig *c = this->list; !has_missing && c != NULL; c = c->next) {
+			has_missing = c->status == GCS_NOT_FOUND || HasBit(c->flags, GCF_COMPATIBLE);
+		}
+		if (has_missing) {
+			this->widget[SNGRFS_CONTENT_DOWNLOAD].data     = STR_CONTENT_INTRO_MISSING_BUTTON;
+			this->widget[SNGRFS_CONTENT_DOWNLOAD].tooltips = STR_CONTENT_INTRO_MISSING_BUTTON_TIP;
+		} else {
+			this->widget[SNGRFS_CONTENT_DOWNLOAD].data     = STR_CONTENT_INTRO_BUTTON;
+			this->widget[SNGRFS_CONTENT_DOWNLOAD].tooltips = STR_CONTENT_INTRO_BUTTON_TIP;
+		}
+
 		this->DrawWidgets();
 
 		/* Draw NewGRF list */
@@ -597,6 +609,8 @@ struct NewGRFWindow : public Window {
 				/* Only show the things in the current list, or everything when nothing's selected */
 					ContentVector cv;
 					for (const GRFConfig *c = this->list; c != NULL; c = c->next) {
+						if (c->status != GCS_NOT_FOUND && !HasBit(c->flags, GCF_COMPATIBLE)) continue;
+
 						ContentInfo *ci = new ContentInfo();
 						ci->type = CONTENT_TYPE_NEWGRF;
 						ci->state = ContentInfo::DOES_NOT_EXIST;