diff --git a/src/common/audio/sound/i_sound.cpp b/src/common/audio/sound/i_sound.cpp
index 6855ce51b5..5f828d9854 100644
--- a/src/common/audio/sound/i_sound.cpp
+++ b/src/common/audio/sound/i_sound.cpp
@@ -367,7 +367,7 @@ SoundHandle SoundRenderer::LoadSoundVoc(uint8_t *sfxdata, int length)
 			i += 4;
 			if (i + blocksize > length)
 			{
-				okay = false;
+				//okay = false;
 				break;
 			}
 
@@ -450,7 +450,7 @@ SoundHandle SoundRenderer::LoadSoundVoc(uint8_t *sfxdata, int length)
 		}
 
 		// Second pass to write the data
-		if (okay)
+		if (okay && len > 0)
 		{
 			data = new uint8_t[len];
 			i = 26;
diff --git a/src/common/filesystem/file_zip.cpp b/src/common/filesystem/file_zip.cpp
index f33b60ba4a..0096507bfd 100644
--- a/src/common/filesystem/file_zip.cpp
+++ b/src/common/filesystem/file_zip.cpp
@@ -208,8 +208,9 @@ bool FZipFile::Open(bool quiet, LumpFilterInfo* filter)
 	char *dirptr = (char*)directory;
 	FZipLump *lump_p = Lumps;
 
-	FString name0;
+	FString name0, name1;
 	bool foundspeciallump = false;
+	bool foundprefix = false;
 
 	// Check if all files have the same prefix so that this can be stripped out.
 	// This will only be done if there is either a MAPINFO, ZMAPINFO or GAMEINFO lump in the subdirectory, denoting a ZDoom mod.
@@ -234,31 +235,39 @@ bool FZipFile::Open(bool quiet, LumpFilterInfo* filter)
 
 		name.ToLower();
 		if (name.IndexOf("__macosx") == 0) 
-			continue; // skip Apple garbage. At this stage only the root folder matters,
-		if (i == 0)
+			continue; // skip Apple garbage. At this stage only the root folder matters.
+		if (!foundprefix)
 		{
 			// check for special names, if one of these gets found this must be treated as a normal zip.
 			bool isspecial = name.IndexOf("/") < 0 || (filter && filter->reservedFolders.Find(name) < filter->reservedFolders.Size());
 			if (isspecial) break;
 			name0 = name.Left(name.LastIndexOf("/")+1);
+			name1 = name.Left(name.IndexOf("/") + 1);
+			foundprefix = true;
 		}
-		else
+
+		if (name.IndexOf(name0) != 0)
 		{
-			if (name.IndexOf(name0) != 0)
+			if (name1.IsNotEmpty())
 			{
-				name0 = "";
-				break;
+				name0 = name1;
+				if (name.IndexOf(name0) != 0)
+				{
+					name0 = "";
+				}
 			}
-			else if (!foundspeciallump && filter)
-			{
-				// at least one of the more common definition lumps must be present.
-				for (auto &p : filter->requiredPrefixes)
-				{ 
-					if (name.IndexOf(name0 + p) == 0 || name.LastIndexOf(p) == name.Len() - strlen(p))
-					{
-						foundspeciallump = true;
-						break;
-					}
+			if (name0.IsEmpty()) 
+				break;
+		}
+		if (!foundspeciallump && filter)
+		{
+			// at least one of the more common definition lumps must be present.
+			for (auto &p : filter->requiredPrefixes)
+			{ 
+				if (name.IndexOf(name0 + p) == 0 || name.LastIndexOf(p) == name.Len() - strlen(p))
+				{
+					foundspeciallump = true;
+					break;
 				}
 			}
 		}
diff --git a/src/common/platform/posix/sdl/sdlglvideo.cpp b/src/common/platform/posix/sdl/sdlglvideo.cpp
index 43bd99a64c..4f7dc6e88f 100644
--- a/src/common/platform/posix/sdl/sdlglvideo.cpp
+++ b/src/common/platform/posix/sdl/sdlglvideo.cpp
@@ -115,8 +115,6 @@ CCMD(vid_list_sdl_render_drivers)
 
 namespace Priv
 {
-	static const uint32_t VulkanWindowFlag = SDL_WINDOW_VULKAN;
-
 	SDL_Window *window;
 	bool vulkanEnabled;
 	bool softpolyEnabled;
@@ -408,7 +406,7 @@ SDLVideo::SDLVideo ()
 
 	if (Priv::vulkanEnabled)
 	{
-		Priv::CreateWindow(Priv::VulkanWindowFlag | SDL_WINDOW_HIDDEN);
+		Priv::CreateWindow(SDL_WINDOW_VULKAN | SDL_WINDOW_HIDDEN | (vid_fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0));
 
 		if (Priv::window == nullptr)
 		{
diff --git a/src/common/rendering/hwrenderer/data/hw_shadowmap.cpp b/src/common/rendering/hwrenderer/data/hw_shadowmap.cpp
index f3e37ed614..cb5630594a 100644
--- a/src/common/rendering/hwrenderer/data/hw_shadowmap.cpp
+++ b/src/common/rendering/hwrenderer/data/hw_shadowmap.cpp
@@ -85,7 +85,7 @@ CUSTOM_CVAR(Int, gl_shadowmap_quality, 512, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 
 bool IShadowMap::ShadowTest(const DVector3 &lpos, const DVector3 &pos)
 {
-	if (mAABBTree)
+	if (mAABBTree && gl_light_shadowmap)
 		return mAABBTree->RayTest(lpos, pos) >= 1.0f;
 	else
 		return true;
@@ -98,7 +98,7 @@ bool IShadowMap::PerformUpdate()
 	LightsProcessed = 0;
 	LightsShadowmapped = 0;
 
-	if (CollectLights != nullptr)
+	if (gl_light_shadowmap && (screen->hwcaps & RFL_SHADER_STORAGE_BUFFER) && CollectLights != nullptr)
 	{
 		UpdateCycles.Clock();
 		UploadAABBTree();