diff --git a/SKSE/Plugins/fs.dll b/SKSE/Plugins/fs.dll
index 47a78d76..38c5ad55 100644
--- a/SKSE/Plugins/fs.dll
+++ b/SKSE/Plugins/fs.dll
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:99c536fbac8293f73b56ae823c24b95457237000fd0e689729845fa9ded036a0
-size 176128
+oid sha256:01930a8819132b7eb415fce927d23bc9cade2c102c842c082db642264c3609a5
+size 202240
diff --git a/SKSE/Plugins/fs_se.dll b/SKSE/Plugins/fs_se.dll
index 2cdd1600..6aa0303f 100644
--- a/SKSE/Plugins/fs_se.dll
+++ b/SKSE/Plugins/fs_se.dll
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:0f903c871bf8231f023cf5220b858e2db7ea774bc9dec82ee448f092e196664f
-size 176128
+oid sha256:a386d7e1126bb9c5c81f36337064fa60aa6ed5403ed56b32f9ef9927b939d9de
+size 200704
diff --git a/scripts/_00e_playersetupscript.pex b/scripts/_00e_playersetupscript.pex
index 97a20192..4981877e 100644
Binary files a/scripts/_00e_playersetupscript.pex and b/scripts/_00e_playersetupscript.pex differ
diff --git a/scripts/enderallib.pex b/scripts/enderallib.pex
index a7411c88..9c12b6d3 100644
Binary files a/scripts/enderallib.pex and b/scripts/enderallib.pex differ
diff --git a/source/fs.dll/fs/HasInvalidCells.h b/source/fs.dll/fs/HasInvalidCells.h
new file mode 100644
index 00000000..6d96a9ac
--- /dev/null
+++ b/source/fs.dll/fs/HasInvalidCells.h
@@ -0,0 +1,612 @@
+#pragma once
+
+#include "skse64/GameForms.h"
+
+inline bool HasInvalidCells()
+{
+	// FormIDs of all Skyrim cells.
+	// 7 of them are commented out, because they are cells in Enderal as well.
+
+	UInt32 formids[584] = {
+		0x0004B8FB,
+		0x000352C7,
+		0x000161E7,
+		0x00013A73,
+		0x000BA599,
+		0x00042BED,
+		0x000361F9,
+		0x00016A11,
+		0x000152A1,
+		0x0001523D,
+		0x000A8B23,
+		0x000918D3,
+		0x0004761B,
+		0x0003CBCB,
+		0x00016A07,
+		0x00015233,
+		0x000138CF,
+		0x0009CCDD,
+		0x0008B84D,
+		0x0003EA9D,
+		0x000198DD,
+		0x000165B1,
+		0x00015229,
+		0x000D9DC7,
+		0x000965B3,
+		0x0006F3EB,
+		0x000466CB,
+		0x000165A7,
+		0x00015283,
+		0x000139E7,
+		0x000EF325,
+		0x000AD5A1,
+		0x00016BDD,
+		0x00015279,
+		0x00015215,
+		0x00013979,
+		0x0007BEF7,
+		0x0004E227,
+		0x000240B7,
+		0x00016BD3,
+		0x00016787,
+		0x0001526F,
+		0x0005015D,
+		0x0002E521,
+		0x0001677D,
+		0x00016205,
+		0x00015265,
+		0x00015201,
+		0x00013901,
+		0x0007BC27,
+		0x0002D3E7,
+		0x0001B147,
+		0x0001A337,
+		0x000196B7,
+		0x000161FB,
+		0x00013A87,
+		0x00033779,
+		0x0002D5D1,
+		0x000161F1,
+		0x00015251,
+		0x00013A7D,
+		0x00030442,
+		0x000152AA,
+		0x00013A72,
+		0x000571B4,
+		0x00042BEC,
+		0x00037EE0,
+		0x00016A10,
+		0x000152A0,
+		0x0001523C,
+		0x00013A68,
+		0x00013810,
+		0x0001DB4E,
+		0x00016A06,
+		0x00015296,
+		0x000138CE,
+		0x0001528C,
+		0x000371DE,
+		0x00036A72,
+		0x000165A6,
+		//0x00015282,
+		0x00013856,
+		0x000EF324,
+		0x000EB440,
+		0x0009B238,
+		0x00081DEC,
+		0x0007144C,
+		0x0005DE24,
+		0x000597D4,
+		0x00016BDC,
+		0x00013978,
+		0x00065AB6,
+		0x0001D09A,
+		0x00016BD2,
+		0x00016786,
+		0x0001526E,
+		0x0001520A,
+		0x000139D2,
+		0x000F39C4,
+		0x000A9194,
+		0x0005015C,
+		0x00035604,
+		0x00033D68,
+		0x0001677C,
+		0x00016204,
+		0x00015200,
+		0x000B6BE6,
+		0x000A95D6,
+		0x0009AA4A,
+		0x0006C3B6,
+		0x000152BE,
+		0x000151F6,
+		0x00013A86,
+		0x0001382E,
+		0x0001AB60,
+		0x00019454,
+		0x000161F0,
+		0x000152B4,
+		0x00013A7C,
+		0x000F7631,
+		0x00053081,
+		0x000529DD,
+		0x0003538D,
+		0x00013A71,
+		0x000138E1,
+		0x001037E7,
+		0x0005C483,
+		0x00047817,
+		0x00022F53,
+		0x00016DF7,
+		0x00016A0F,
+		0x0001529F,
+		0x00013A67,
+		0x0001380F,
+		0x00016A05,
+		0x00015295,
+		0x00015231,
+		0x00013A5D,
+		0x000138CD,
+		0x0005B91B,
+		0x000165AF,
+		0x00015227,
+		0x0001321F,
+		0x0005D01D,
+		0x000371DD,
+		0x00025195,
+		0x00016EA1,
+		0x00015281,
+		0x0007C98B,
+		0x00052FEB,
+		0x00028EDF,
+		0x000243DF,
+		0x0001F7B3,
+		0x00016BDB,
+		0x00015277,
+		0x00065AB5,
+		0x0005B5DD,
+		0x0003B87D,
+		0x0002D525,
+		0x0002C779,
+		0x00016BD1,
+		0x00016785,
+		0x0001526D,
+		0x000139D1,
+		0x00013909,
+		//0x00000025,
+		0x000AE783,
+		0x000A0877,
+		0x0006CCBB,
+		0x000317E7,
+		0x00016203,
+		0x000A87C5,
+		0x000A0359,
+		0x000152BD,
+		0x000151F5,
+		0x00013A85,
+		0x0001382D,
+		0x00028ACF,
+		0x0001AB5F,
+		0x000161EF,
+		0x00013A7B,
+		0x000547F0,
+		0x00021594,
+		0x000213A0,
+		0x00016E00,
+		0x000152A8,
+		0x00013818,
+		0x00022F52,
+		0x00016DF6,
+		//0x00016A0E,
+		0x00013A66,
+		0x0001380E,
+		0x000B64B4,
+		0x00056E88,
+		0x0001B7C0,
+		0x00016A04,
+		0x00015294,
+		0x00015230,
+		0x00013A5C,
+		0x000138CC,
+		0x00080C6A,
+		0x0005A01A,
+		0x0002031A,
+		0x0001E11E,
+		0x000165AE,
+		0x0001528A,
+		0x00015226,
+		0x00075270,
+		0x0003A184,
+		0x00034B94,
+		0x00015280,
+		0x0001521C,
+		0x00013A48,
+		//0x0010CEEA,
+		0x00016BDA,
+		0x00015276,
+		0x000DB070,
+		0x0003DD34,
+		0x0002D524,
+		0x0002C778,
+		0x0001CB84,
+		0x00016BD0,
+		0x00016784,
+		0x0001526C,
+		0x00015208,
+		0x0001677A,
+		0x00015262,
+		0x00069858,
+		0x00015258,
+		0x000151F4,
+		0x00013A84,
+		0x000B29D6,
+		0x000A6D8E,
+		0x0008CDEE,
+		0x00054D0E,
+		0x000527F2,
+		0x00027552,
+		0x000193EE,
+		0x000161EE,
+		0x0001605E,
+		0x00013A7A,
+		0x000C9DAB,
+		0x000A1793,
+		0x00094BAB,
+		0x00030313,
+		0x00016DFF,
+		0x000152A7,
+		0x0007FCDD,
+		0x000414DD,
+		0x000399D1,
+		0x00016DF5,
+		0x00016A0D,
+		0x0001529D,
+		0x00015239,
+		0x00013871,
+		0x000F2CAB,
+		0x000A013B,
+		0x0005A857,
+		0x0001AEC3,
+		0x00016A03,
+		0x000165B7,
+		0x0001522F,
+		0x000138CB,
+		0x00013867,
+		0x000165AD,
+		0x00056C1B,
+		//0x000446BF,
+		0x0004401B,
+		0x0003A183,
+		0x000263EF,
+		0x000165A3,
+		0x0001527F,
+		0x0001521B,
+		0x000AB531,
+		0x00083559,
+		0x0005912D,
+		0x00016BD9,
+		0x00015275,
+		0x00015211,
+		0x0003D62B,
+		0x00016BCF,
+		0x0001620B,
+		0x0001526B,
+		0x00015207,
+		0x00013907,
+		0x000A1BFD,
+		0x00052CB5,
+		0x00034B75,
+		0x00016779,
+		0x00015261,
+		0x000EA28B,
+		0x000BBB2F,
+		0x000B1783,
+		0x00079F9F,
+		0x00039F67,
+		0x0002BCD7,
+		0x000270AB,
+		0x000161F7,
+		0x000152BB,
+		0x00015257,
+		0x000151F3,
+		0x00013A83,
+		0x000EEC55,
+		0x000B29D5,
+		0x000161ED,
+		0x000152B1,
+		0x00013A79,
+		0x00016DFE,
+		0x000133CA,
+		0x0006DAA0,
+		0x00052390,
+		0x00016DF4,
+		0x00016A0C,
+		0x0001529C,
+		0x00015238,
+		0x00013870,
+		//0x000B9BC6,
+		0x0005A856,
+		0x0002471A,
+		0x000198E2,
+		0x00016A02,
+		0x000165B6,
+		0x000138CA,
+		0x00059398,
+		0x0003E908,
+		0x000165AC,
+		0x00015288,
+		0x00015224,
+		0x000CAB92,
+		0x0005F536,
+		0x0002A976,
+		0x00016D72,
+		0x0001527E,
+		0x000C7348,
+		0x000AA20C,
+		0x000A73F4,
+		0x00095C44,
+		0x0006E2AC,
+		0x0005D010,
+		0x00018BE0,
+		0x00016BD8,
+		0x0001678C,
+		0x00015274,
+		0x00015210,
+		0x000C0BBA,
+		0x000280C2,
+		0x00016BCE,
+		0x00016782,
+		0x0001526A,
+		0x00015206,
+		0x000F5EDC,
+		0x000ED8E0,
+		0x0007DCFC,
+		0x00018460,
+		0x00016778,
+		0x00016200,
+		0x00015260,
+		0x000151FC,
+		0x00013A8C,
+		0x0005554A,
+		0x00054226,
+		0x0003D35A,
+		0x00037B76,
+		0x000161F6,
+		0x000152BA,
+		0x000151F2,
+		0x000B29D4,
+		0x0003FF10,
+		0x0002E760,
+		0x000161EC,
+		0x000152B0,
+		0x00013A78,
+		0x000ABD31,
+		0x00055215,
+		0x0002954D,
+		0x00016DFD,
+		0x000152A5,
+		0x000133C9,
+		0x0005EAC7,
+		0x00058663,
+		0x000336FB,
+		0x00016DF3,
+		0x00016A0B,
+		0x00015237,
+		0x00077289,
+		0x00075669,
+		0x0002FD85,
+		0x000165B5,
+		0x0003FC8F,
+		0x000165AB,
+		0x00015223,
+		0x000CAB91,
+		0x00068B99,
+		0x0004C6DD,
+		0x00035299,
+		0x00018BE9,
+		0x0001527D,
+		0x00043FAB,
+		0x00016BD7,
+		0x0001678B,
+		0x00015273,
+		0x000DEBCD,
+		0x00078715,
+		0x0001F359,
+		0x00016781,
+		0x00016209,
+		0x00015269,
+		0x0005B88B,
+		0x0005723B,
+		0x00016777,
+		0x000161FF,
+		0x000152C3,
+		0x0001525F,
+		0x000151FB,
+		0x000A5A71,
+		//0x000A1A61,
+		0x000778F1,
+		0x00045A1D,
+		0x000161F5,
+		0x00015255,
+		0x00013A81,
+		0x000EEC53,
+		0x00081D5B,
+		0x000161EB,
+		0x000152AF,
+		0x00054B70,
+		0x0005258C,
+		0x000471DC,
+		0x0002954C,
+		0x00016DFC,
+		0x00013814,
+		0x000133C8,
+		0x000DBF12,
+		0x000CCDAA,
+		0x00091872,
+		0x00036ED6,
+		0x00016DF2,
+		0x00034BA4,
+		0x0002D4E4,
+		0x00025E24,
+		0x000198E0,
+		0x00016A00,
+		0x00015290,
+		0x0001522C,
+		0x0007947A,
+		0x000165AA,
+		0x00015286,
+		0x000138BE,
+		0x00087764,
+		0x0003B698,
+		0x000165A0,
+		0x0001527C,
+		0x00013850,
+		0x0008E906,
+		0x00071FFE,
+		0x00016BD6,
+		0x000C5AA0,
+		0x0001F358,
+		0x00016780,
+		0x00015268,
+		0x0002F83E,
+		0x0002529E,
+		0x00016776,
+		0x000161FE,
+		0x000151FA,
+		0x00013A8A,
+		0x00078124,
+		0x000362D8,
+		0x00023FD4,
+		0x0001FA4C,
+		0x000161F4,
+		0x00015254,
+		0x00013A80,
+		0x000BBCB2,
+		0x000AC5D2,
+		0x00081972,
+		0x000261C6,
+		0x000161EA,
+		0x000152AE,
+		0x00013A76,
+		0x00054B6F,
+		0x00032AE7,
+		0x000216BB,
+		0x00016DFB,
+		0x0001523F,
+		0x00013813,
+		0x000133C7,
+		0x00070469,
+		0x00036ED5,
+		0x00034955,
+		0x00016A09,
+		0x00015235,
+		0x0009CCDF,
+		0x0007B7AB,
+		0x0002D4E3,
+		0x000198DF,
+		0x000165B3,
+		0x00097299,
+		0x00089D51,
+		0x000681DD,
+		0x00024771,
+		0x000AF227,
+		0x0007D033,
+		0x00041777,
+		0x00016BDF,
+		0x0001527B,
+		0x00058B4D,
+		0x000275D9,
+		0x000227B9,
+		0x00016BD5,
+		0x00016789,
+		0x000FE47B,
+		0x0001677F,
+		0x00016207,
+		0x00015267,
+		0x001052FD,
+		0x00104871,
+		0x0002F83D,
+		0x00016775,
+		0x000152C1,
+		0x0001525D,
+		0x000151F9,
+		0x00013A89,
+		0x000961FF,
+		0x0007E00F,
+		0x0004624F,
+		0x000161F3,
+		0x000152B7,
+		0x00015253,
+		0x00013A7F,
+		0x000221B5,
+		0x000161E9,
+		0x000152AD,
+		0x0009174E,
+		0x0004A376,
+		0x000361FA,
+		0x0002A03A,
+		0x00016DFA,
+		0x000152A2,
+		0x00013812,
+		0x000133C6,
+		0x000DDF7C,
+		0x000A8B24,
+		0x00016A08,
+		0x000138D0,
+		0x0001386C,
+		0x000BE46A,
+		0x0009CCDE,
+		0x0007284E,
+		0x00067F2A,
+		0x0003016A,
+		0x000198DE,
+		0x000169FE,
+		0x000165B2,
+		0x0001522A,
+		0x00097298,
+		0x0007614C,
+		0x000165A8,
+		0x00015284,
+		0x00015220,
+		0x000DD216,
+		0x000563E2,
+		0x00050F1E,
+		0x0003F516,
+		0x0003B696,
+		0x00037CC6,
+		0x0003486E,
+		0x0001FC66,
+		0x00016BDE,
+		0x0007BEF8,
+		0x00058B4C,
+		0x00034864,
+		0x000275D8,
+		0x00016BD4,
+		0x00016788,
+		0x0001677E,
+		0x0001383A,
+		0x0002D3E8,
+		0x00016774,
+		0x000161FC,
+		0x000152C0,
+		0x0001525C,
+		0x00013A88,
+		0x00094322,
+		0x000580A2,
+		0x00027F1A,
+		0x0001CE8A,
+		0x00013A7E,
+		0x00039850,
+		0x00027D1C
+	};
+
+	bool result = false;
+	for (int i = 0; i < 415; i++) {
+		if ((TESObjectCELL*)LookupFormByID(formids[i])) {
+			_MESSAGE("Detected invalid cell: %#08x", formids[i]);
+			result = true;
+		}
+	}
+
+	return result;
+}
diff --git a/source/fs.dll/fs/fs.vcxproj b/source/fs.dll/fs/fs.vcxproj
index ecf38269..aa579250 100644
--- a/source/fs.dll/fs/fs.vcxproj
+++ b/source/fs.dll/fs/fs.vcxproj
@@ -164,6 +164,7 @@
       <WarningLevel>Level3</WarningLevel>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <ForcedIncludeFiles>common/IPrefix.h;%(ForcedIncludeFiles)</ForcedIncludeFiles>
+      <LanguageStandard>stdcpp17</LanguageStandard>
     </ClCompile>
     <Link>
       <ModuleDefinitionFile>exports.def</ModuleDefinitionFile>
@@ -181,6 +182,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="CreatePotion.h" />
+    <ClInclude Include="HasInvalidCells.h" />
     <ClInclude Include="PhasmalistInventoryFunctions.h" />
   </ItemGroup>
   <ItemGroup>
diff --git a/source/fs.dll/fs/main.cpp b/source/fs.dll/fs/main.cpp
index b2f6ec40..2506871c 100644
--- a/source/fs.dll/fs/main.cpp
+++ b/source/fs.dll/fs/main.cpp
@@ -1,9 +1,11 @@
 #include "skse64/PluginAPI.h"		// super
 #include "skse64_common/skse_version.h"	// What version of SKSE is running?
 #include <shlobj.h>				// CSIDL_MYCODUMENTS
+#include <filesystem>
 
 #include "PhasmalistInventoryFunctions.h"
 #include "CreatePotion.h"
+#include "HasInvalidCells.h"
 
 static SKSEPapyrusInterface         * g_papyrus = NULL;
 static SInt32 g_NewGameStarted = 0;
@@ -51,7 +53,27 @@ struct SKSEPluginVersionData
 
 void SKSEMessageHandler(SKSEMessagingInterface::Message* msg)
 {
-	if ((msg->type == SKSEMessagingInterface::kMessage_PostLoadGame && msg->data) || msg->type == SKSEMessagingInterface::kMessage_NewGame) {
+	if (msg->type == SKSEMessagingInterface::kMessage_PostLoad) {
+		if (std::filesystem::file_size("Data\\Dawnguard.esm") > 100000 || std::filesystem::file_size("Data\\Dragonborn.esm") > 100000 || std::filesystem::file_size("Data\\HearthFires.esm") > 100000 || std::filesystem::file_size("Data\\Update.esm") > 150000) {
+			MessageBox(NULL, "Skyrim DLCs are incompatible with Enderal!", "Error", MB_OK | MB_ICONERROR);
+			exit(EXIT_FAILURE);
+		}
+		if (std::filesystem::exists("Data\\Unofficial Skyrim Special Edition Patch.esp")) {
+			MessageBox(NULL, "Unofficial Skyrim Special Edition Patch is incompatible with Enderal!", "Error", MB_OK | MB_ICONERROR);
+			exit(EXIT_FAILURE);
+		}
+		if (std::filesystem::exists("Data\\ccBGSSSE001-Fish.esm") || std::filesystem::exists("Data\\ccBGSSSE025-AdvDSGS.esm") || std::filesystem::exists("Data\\ccBGSSSE037-Curios.esl") || std::filesystem::exists("Data\\ccQDRSSE001-SurvivalMode.esl")) {
+			MessageBox(NULL, "Creation Club mods are incompatible with Enderal!", "Error", MB_OK | MB_ICONERROR);
+			exit(EXIT_FAILURE);
+		}
+	}
+	else if (msg->type == SKSEMessagingInterface::kMessage_DataLoaded) {
+		TESWorldSpace* world = (TESWorldSpace*)LookupFormByID(0x3C);
+		if ((world && std::string(world->editorId.Get()) != "MQP01Home") || HasInvalidCells()) {
+			MessageBox(NULL, "Some installed mods are incompatible with Enderal!", "Error", MB_OK | MB_ICONERROR);
+		}
+	}
+	else if ((msg->type == SKSEMessagingInterface::kMessage_PostLoadGame && msg->data) || msg->type == SKSEMessagingInterface::kMessage_NewGame) {
 		if (g_NewGameStarted < 2) {
 			g_NewGameStarted++;
 		}
@@ -155,18 +177,6 @@ extern "C" {
 			return true;
 		});
 
-		g_papyrus->Register([](VMClassRegistry* registry) {
-			registry->RegisterFunction(new NativeFunction0<StaticFunctionTag, bool>("HasIncompatibleMods", "EnderalLib", [](StaticFunctionTag* tag) {
-				TESWorldSpace* world = (TESWorldSpace*)LookupFormByID(0x3C);
-				if (world && std::string(world->editorId.Get()) != "MQP01Home") {
-					return true;
-				}
-				return false;
-			}, registry));
-			_MESSAGE("Register Succeeded: HasIncompatibleMods");
-			return true;
-		});
-
 		return true;
 	}
 };
\ No newline at end of file
diff --git a/source/scripts/_00e_playersetupscript.psc b/source/scripts/_00e_playersetupscript.psc
index 76683ee4..890f95a6 100644
--- a/source/scripts/_00e_playersetupscript.psc
+++ b/source/scripts/_00e_playersetupscript.psc
@@ -394,11 +394,6 @@ Function Maintenance()
 	If Game.GetModByName("Enderal_FS_More_Affinities.esp") != 255
 		FixMoreAffinitiesMod()
 	EndIf
-	
-	if EnderalLib.NewGameCount() == 1 && EnderalLib.HasIncompatibleMods()
-		Utility.wait(2.0)
-		Debug.Notification("Some installed mods are incompatible with Enderal.")
-	endif
 
 EndFunction
 
diff --git a/source/scripts/enderallib.psc b/source/scripts/enderallib.psc
index e4bf82db..5feba6de 100644
--- a/source/scripts/enderallib.psc
+++ b/source/scripts/enderallib.psc
@@ -6,8 +6,6 @@ Potion function CreatePotion(MagicEffect[] effects, float[] magnitudes, int[] ar
 
 int function NewGameCount() native global
 
-bool function HasIncompatibleMods() native global
-
 bool function IsDLLLoaded() global
 	return (SKSE.GetPluginVersion("fs_skse_functions") != -1)
 endfunction