diff --git a/gradle.properties b/gradle.properties
index fb5909596..10068585a 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -5,11 +5,11 @@ group=grondag
 mod_name=canvas
 canvas_version=1.0
 
-fermion_version=2.0
+fermion_version=2.1
 special_circumstances_version=1.6
-fermion_varia_version=2.0
+fermion_varia_version=2.1
 fermion_orientation_version=1.0
-frex_version=2.2
+frex_version=2.3
 
 jankson_version=3.0.0+j1.2.0
 clothconfig_version=4.5.3
diff --git a/src/main/java/grondag/canvas/light/LightmapHdCalc.java b/src/main/java/grondag/canvas/light/LightmapHdCalc.java
index b90db54f4..f21554609 100644
--- a/src/main/java/grondag/canvas/light/LightmapHdCalc.java
+++ b/src/main/java/grondag/canvas/light/LightmapHdCalc.java
@@ -254,39 +254,39 @@ static void computeAo(int[] light, AoFaceData faceData) {
 		//		}
 	}
 
-	private static void computeQuadrantAo(float center, float uSide, float vSide, float corner, int light[], Int2IntFunction uFunc, Int2IntFunction vFunc) {
-		//FIX: handle error case when center is missing
-		if(uSide == AoFaceData.OPAQUE) {
-			if(vSide == AoFaceData.OPAQUE) {
-				// fully enclosed
-				computeOpen(center, center - 0.5f, center - 0.5f, center - 0.5f, light, uFunc, vFunc);
-			} else if (corner == AoFaceData.OPAQUE) {
-				// U + corner enclosing
-				uSide = center - 0.25f;
-				computeClamped(center, uSide, (vSide + center) * 0.5f, (uSide + vSide - 0.25f) * 0.5f, light, uFunc, vFunc);
-			} else {
-				// U side enclosing
-				final float join = (center + vSide + corner) / 3f;
-				computeClamped(center, center - 0.25f, (vSide + center) * 0.5f, join, light, uFunc, vFunc);
-			}
-		} else if(vSide == AoFaceData.OPAQUE) {
-			if(corner == AoFaceData.OPAQUE) {
-				// V + corner enclosing
-				vSide = center - 0.25f;
-				computeClamped(center, (uSide + center) * 0.5f, vSide, (uSide + vSide - 0.25f) * 0.5f, light, uFunc, vFunc);
-			} else {
-				// V side enclosing
-				final float join = (center + uSide + corner) / 3f;
-				computeClamped(center, (uSide + center) * 0.5f, center - 0.25f, join, light, uFunc, vFunc);
-			}
-
-		} else if(corner == AoFaceData.OPAQUE) {
-			// opaque corner
-			final float join = (center + uSide + vSide) / 3f;
-			computeClamped(center, (uSide + center) * 0.5f, (vSide + center) * 0.5f, join, light, uFunc, vFunc);
-		} else {
-			// all open
-			computeOpen(center, uSide, vSide, corner, light, uFunc, vFunc);
-		}
-	}
+	//	private static void computeQuadrantAo(float center, float uSide, float vSide, float corner, int light[], Int2IntFunction uFunc, Int2IntFunction vFunc) {
+	//		//FIX: handle error case when center is missing
+	//		if(uSide == AoFaceData.OPAQUE) {
+	//			if(vSide == AoFaceData.OPAQUE) {
+	//				// fully enclosed
+	//				computeOpen(center, center - 0.5f, center - 0.5f, center - 0.5f, light, uFunc, vFunc);
+	//			} else if (corner == AoFaceData.OPAQUE) {
+	//				// U + corner enclosing
+	//				uSide = center - 0.25f;
+	//				computeClamped(center, uSide, (vSide + center) * 0.5f, (uSide + vSide - 0.25f) * 0.5f, light, uFunc, vFunc);
+	//			} else {
+	//				// U side enclosing
+	//				final float join = (center + vSide + corner) / 3f;
+	//				computeClamped(center, center - 0.25f, (vSide + center) * 0.5f, join, light, uFunc, vFunc);
+	//			}
+	//		} else if(vSide == AoFaceData.OPAQUE) {
+	//			if(corner == AoFaceData.OPAQUE) {
+	//				// V + corner enclosing
+	//				vSide = center - 0.25f;
+	//				computeClamped(center, (uSide + center) * 0.5f, vSide, (uSide + vSide - 0.25f) * 0.5f, light, uFunc, vFunc);
+	//			} else {
+	//				// V side enclosing
+	//				final float join = (center + uSide + corner) / 3f;
+	//				computeClamped(center, (uSide + center) * 0.5f, center - 0.25f, join, light, uFunc, vFunc);
+	//			}
+	//
+	//		} else if(corner == AoFaceData.OPAQUE) {
+	//			// opaque corner
+	//			final float join = (center + uSide + vSide) / 3f;
+	//			computeClamped(center, (uSide + center) * 0.5f, (vSide + center) * 0.5f, join, light, uFunc, vFunc);
+	//		} else {
+	//			// all open
+	//			computeOpen(center, uSide, vSide, corner, light, uFunc, vFunc);
+	//		}
+	//	}
 }
diff --git a/src/main/java/grondag/canvas/shader/GlShader.java b/src/main/java/grondag/canvas/shader/GlShader.java
index e01ada247..528af947e 100644
--- a/src/main/java/grondag/canvas/shader/GlShader.java
+++ b/src/main/java/grondag/canvas/shader/GlShader.java
@@ -166,6 +166,8 @@ private static void clearDebugSource() {
 		}
 	}
 
+	private static boolean needsDebugOutputWarning = true;
+
 	private void outputDebugSource(String source, String error) {
 		final String key = shaderSource.toString().replace("/", "-") + "."  + context.name;
 		final File gameDir = FabricLoader.getInstance().getGameDirectory();
@@ -190,7 +192,10 @@ private void outputDebugSource(String source, String error) {
 				writer.write(source);
 				writer.close();
 			} catch (final IOException e) {
-				// TODO: log failure to output source
+				if (needsDebugOutputWarning) {
+					CanvasMod.LOG.error(I18n.translate("error.canvas.fail_create_shader_output", shaderDir), e);
+					needsDebugOutputWarning = false;
+				}
 			}
 		}
 	}
diff --git a/src/main/resources/assets/canvas/lang/en_us.json b/src/main/resources/assets/canvas/lang/en_us.json
index 95acdd66d..ad0bdbf1b 100644
--- a/src/main/resources/assets/canvas/lang/en_us.json
+++ b/src/main/resources/assets/canvas/lang/en_us.json
@@ -2,6 +2,7 @@
 	"debug.canvas.missing_uniform" : "Canvas unable to find uniform %s in shaders %s, %s. This is normal if the uniform isn't used in the shader.",
 	"info.canvas.reloading" : "Canvas Renderer is initializing.",
 	"error.canvas.fail_create_shader" : "Canvas unable to create shader %s with property index %d due to unexpected error: %s.",
+	"error.canvas.fail_create_shader_output" : "Canvas unable to create shader output folder %s due to unexpected error.",
 	"error.canvas.fail_create_any_shader" : "Canvas unable to create one or more shaders due to compilation errors. See canvas_shader_debug folder for details.",
 	"error.canvas.program_link_failure" : "Canvas unable to create linked shader due to unexpected error.",
 	"error.canvas.fail_create_lightmap" : "Canvas unable to create HD lightmap(s) - out of space. \nSome blocks will not render with proper lighting. \nReduce view distance or disable HD lightmaps. F3+A will temporarily clear this problem.",