diff --git a/platformio.ini b/platformio.ini
index 76928d91..056774e8 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -879,6 +879,7 @@ build_flags_XL =
   ; -D USERMOD_SHT ;; experimental
   -D USERMOD_VL53L0X_GESTURES
   -D WLED_ENABLE_PIXART
+  -D USERMOD_ANIMARTRIX ; WLEDMM usermod: CC BY-NC 3.0 licensed effects by Stefan Petrick
 
 lib_deps_XL =
   claws/BH1750 @^1.2.0 ; used for USERMOD_BH1750
diff --git a/wled00/FX.h b/wled00/FX.h
index dcccf850..93293c30 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -727,7 +727,7 @@ class WS2812FX {  // 96 bytes
       _cumulativeFps500(2*500),          // WLEDMM more accurate FPS measurement for ESP32
       _lastShow500(0),
 #endif
-      _isServicing(false),
+      _isServicing(true),            // WLEDMM start with "true" - flag will be reset by strip.finalizeInit()
       _isOffRefreshRequired(false),
       _hasWhiteChannel(false),
       _triggered(false),
@@ -766,6 +766,7 @@ class WS2812FX {  // 96 bytes
       printSize(),
 #endif
       finalizeInit(),
+      waitUntilIdle(void),   // WLEDMM
       service(void),
       setMode(uint8_t segid, uint8_t m),
       setColor(uint8_t slot, uint32_t c),
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index 097fbd64..d3e8213b 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -1424,6 +1424,7 @@ void WS2812FX::enumerateLedmaps() {
 void WS2812FX::finalizeInit(void)
 {
   //reset segment runtimes
+  suspendStripService = true; // WELDMM avoid running effects on an incomplete strip
   for (segment &seg : _segments) {
     seg.markForReset();
     seg.resetIfRequired();
@@ -1503,6 +1504,27 @@ void WS2812FX::finalizeInit(void)
   loadCustomPalettes(); // (re)load all custom palettes
   DEBUG_PRINTLN(F("Loading custom ledmaps"));
   deserializeMap();     // (re)load default ledmap
+  _isServicing = false;        // WLEDMM
+  suspendStripService = false; // WELDMM ready, run !
+}
+
+// WLEDMM wait until strip is idle (=not servicing).
+// on 8266 this function does nothing, because we can only do "buisy waiting" on ESP32
+#define MAX_IDLE_WAIT_MS 50  // seems to work in most cases
+void WS2812FX::waitUntilIdle(void) {
+#ifdef ARDUINO_ARCH_ESP32
+  if (isServicing()) {
+    unsigned long waitStarted = millis();
+    do {
+      delay(1);
+      yield();
+    } while (isServicing() && (millis() - waitStarted < MAX_IDLE_WAIT_MS));
+    USER_PRINTF("strip.waitUntilIdle(): strip %sidle after %d ms. (task %s)\n", isServicing()?"not ":"", int(millis() - waitStarted), pcTaskGetTaskName(NULL));
+  }
+  return;
+#else
+  return;
+#endif
 }
 
 void WS2812FX::service() {
diff --git a/wled00/cfg.cpp b/wled00/cfg.cpp
index 32712fb5..32231ffd 100644
--- a/wled00/cfg.cpp
+++ b/wled00/cfg.cpp
@@ -90,6 +90,19 @@ bool deserializeConfig(JsonObject doc, bool fromFS) {
   // initialize LED pins and lengths prior to other HW (except for ethernet)
   JsonObject hw_led = hw["led"];
 
+  // WLEDMM: before changing strip, make sure our strip is _not_ servicing effects in parallel
+  suspendStripService = true; // temporarily lock out strip updates
+#ifdef ARDUINO_ARCH_ESP32
+  if (strip.isServicing() && (strncmp(pcTaskGetTaskName(NULL), "loopTask", 8) != 0)) { // if we are in looptask (arduino loop), its safe to proceed without waiting
+    if (fromFS) {
+      USER_PRINTLN(F("deserializeConfig(fromFS): strip is still drawing effects, waiting ..."));
+    } else {
+      USER_PRINTLN(F("deserializeConfig(): strip is still drawing effects, waiting ..."));
+    }
+    strip.waitUntilIdle();
+  }
+#endif
+
   uint8_t autoWhiteMode = RGBW_MODE_MANUAL_ONLY;
   CJSON(strip.ablMilliampsMax, hw_led[F("maxpwr")]);
   CJSON(strip.milliampsPerLed, hw_led[F("ledma")]);
@@ -599,6 +612,8 @@ bool deserializeConfig(JsonObject doc, bool fromFS) {
     needsSave = !usermods.readFromConfig(usermods_settings);
   }
 
+  suspendStripService = false; // WLEDMM release lock
+
   if (fromFS) return needsSave;
   // if from /json/cfg
   doReboot = doc[F("rb")] | doReboot;
diff --git a/wled00/json.cpp b/wled00/json.cpp
index 5b4db6af..c0ccbb22 100644
--- a/wled00/json.cpp
+++ b/wled00/json.cpp
@@ -85,8 +85,15 @@ bool deserializeSegment(JsonObject elem, byte it, byte presetId)
     id = strip.getSegmentsNum()-1; // segments are added at the end of list
   }
 
+  // WLEDMM: before changing segments, make sure our strip is _not_ servicing effects in parallel
+  suspendStripService = true; // temporarily lock out strip updates
+  if (strip.isServicing()) {
+    USER_PRINTLN(F("deserializeSegment(): strip is still drawing effects, waiting ..."));
+    strip.waitUntilIdle();
+  }
+
   Segment& seg = strip.getSegment(id);
-  Segment prev = seg; //make a backup so we can tell if something changed
+  Segment prev = seg; //make a backup so we can tell if something changed // WLEDMM fixMe: copy constructor = waste of memory
 
   uint16_t start = elem["start"] | seg.start;
   if (stop < 0) {
@@ -113,6 +120,7 @@ bool deserializeSegment(JsonObject elem, byte it, byte presetId)
       elem["rev"]   = !elem["rev"]; // alternate reverse on even/odd segments
       deserializeSegment(elem, i, presetId); // recursive call with new id
     }
+    suspendStripService = false; // WLEDMM release lock
     return true;
   }
 
@@ -153,7 +161,7 @@ bool deserializeSegment(JsonObject elem, byte it, byte presetId)
   if (map1D2D != M12_jMap && seg.jMap)
     seg.deletejMap();
 
-  if ((spc>0 && spc!=seg.spacing) || seg.map1D2D!=map1D2D) seg.fill(BLACK); // clear spacing gaps
+  if ((spc>0 && spc!=seg.spacing) || seg.map1D2D!=map1D2D) seg.fill(BLACK); // clear spacing gaps // WLEDMM softhack007: this line sometimes crashes with "Stack canary watchpoint triggered (async_tcp)"
 
   seg.map1D2D  = constrain(map1D2D, 0, 7);
   seg.soundSim = constrain(soundSim, 0, 7);
@@ -170,7 +178,10 @@ bool deserializeSegment(JsonObject elem, byte it, byte presetId)
   if (stop > start && of > len -1) of = len -1;
   seg.set(start, stop, grp, spc, of, startY, stopY);
 
-  if (seg.reset && seg.stop == 0) return true; // segment was deleted & is marked for reset, no need to change anything else
+  if (seg.reset && seg.stop == 0) {
+    suspendStripService = false; // WLEDMM release lock
+    return true; // segment was deleted & is marked for reset, no need to change anything else
+  }
 
   byte segbri = seg.opacity;
   if (getVal(elem["bri"], &segbri)) {
@@ -293,7 +304,7 @@ bool deserializeSegment(JsonObject elem, byte it, byte presetId)
     // freeze and init to black
     if (!seg.freeze) {
       seg.freeze = true;
-      seg.fill(BLACK);
+      seg.fill(BLACK);  // WLEDMM why now?
     }
 
     uint16_t start = 0, stop = 0;
@@ -334,6 +345,7 @@ bool deserializeSegment(JsonObject elem, byte it, byte presetId)
   // send UDP/WS if segment options changed (except selection; will also deselect current preset)
   if (seg.differs(prev) & 0x7F) stateChanged = true;
 
+  suspendStripService = false; // WLEDMM release lock
   return true;
 }
 
@@ -389,6 +401,13 @@ bool deserializeState(JsonObject root, byte callMode, byte presetId)
     }
   }
 
+  // WLEDMM: before changing strip, make sure our strip is _not_ servicing effects in parallel
+  suspendStripService = true; // temporarily lock out strip updates
+  if (strip.isServicing()) {
+    USER_PRINTLN(F("deserializeState(): strip is still drawing effects, waiting ..."));
+    strip.waitUntilIdle();
+  }
+
   // temporary transition (applies only once)
   tr = root[F("tt")] | -1;
   if (tr >= 0)
@@ -505,6 +524,7 @@ bool deserializeState(JsonObject root, byte callMode, byte presetId)
       presetCycCurr = ps;
       unloadPlaylist();          // applying a preset unloads the playlist
       applyPreset(ps, callMode); // async load from file system (only preset ID was specified)
+      suspendStripService = false; // WLEDMM release lock
       return stateResponse;
     }
   }
@@ -528,6 +548,7 @@ bool deserializeState(JsonObject root, byte callMode, byte presetId)
   stateUpdated(callMode);
   if (presetToRestore) currentPreset = presetToRestore;
 
+  suspendStripService = false; // WLEDMM release lock
   return stateResponse;
 }
 
diff --git a/wled00/set.cpp b/wled00/set.cpp
index a26e2d78..60ed8ee1 100644
--- a/wled00/set.cpp
+++ b/wled00/set.cpp
@@ -21,6 +21,15 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
   //0: menu 1: wifi 2: leds 3: ui 4: sync 5: time 6: sec 7: DMX 8: usermods 9: N/A 10: 2D
   if (subPage <1 || subPage >10 || !correctPIN) return;
 
+  // WLEDMM: before changing bus or strip settings, make sure our strip is _not_ servicing effects in parallel
+  if ((subPage == 2) || (subPage == 10)) {
+    suspendStripService = true; // temporarily lock out strip updates
+    if (strip.isServicing()) {
+      USER_PRINTLN(F("handleSettingsSet(): strip is still drawing effects, waiting ..."));
+      strip.waitUntilIdle();
+    }
+  }
+
   //WIFI SETTINGS
   if (subPage == 1)
   {
@@ -766,6 +775,10 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
   }
   #endif
 
+  if ((subPage == 2) || (subPage == 10)) {
+    suspendStripService = false; // WLEDMM release lock
+  }
+
   lastEditTime = millis();
   if (subPage != 2 && !doReboot) doSerializeConfig = true; //serializeConfig(); //do not save if factory reset or LED settings (which are saved after LED re-init)
   #ifndef WLED_DISABLE_ALEXA
@@ -802,6 +815,12 @@ bool handleSet(AsyncWebServerRequest *request, const String& req, bool apply)
     }
   }
 
+  // WLEDMM: before changing segment settings, make sure our strip is _not_ servicing effects in parallel
+  if (strip.isServicing()) {
+      USER_PRINTLN(F("handleSet(): strip is still drawing effects, waiting ..."));
+      strip.waitUntilIdle();
+  }
+
   Segment& selseg = strip.getSegment(selectedSeg);
   pos = req.indexOf(F("SV=")); //segment selected
   if (pos > 0) {
diff --git a/wled00/wled.cpp b/wled00/wled.cpp
index 3774fe77..38d38555 100644
--- a/wled00/wled.cpp
+++ b/wled00/wled.cpp
@@ -164,8 +164,17 @@ void WLED::loop()
     #ifdef WLED_DEBUG
     unsigned long stripMillis = millis();
     #endif
-    if (!offMode || strip.isOffRefreshRequired())
-      strip.service();
+    if (!offMode || strip.isOffRefreshRequired()) {
+      static unsigned long lastTimeService = 0; // WLEMM needed to remove stale lock
+      if (!suspendStripService && !doInitBusses && !loadLedmap) { // WLEDMM prevent effect drawing while strip or segments are being updated
+        strip.service();
+        lastTimeService = millis();
+      } else {
+        if (suspendStripService && (millis() - lastTimeService > 1500)) { // WLEDMM remove stale lock after 1.5 seconds
+          USER_PRINTLN("--> looptask: stale suspendStripService lock removed after 1500 ms."); // should not happen - check for missing "suspendStripService = false"
+        }
+      }
+    }
     #ifdef ESP8266
     else if (!noWifiSleep)
       delay(1); //required to make sure ESP enters modem sleep (see #1184)
diff --git a/wled00/wled.h b/wled00/wled.h
index f8ce04e3..6bb401f1 100644
--- a/wled00/wled.h
+++ b/wled00/wled.h
@@ -8,7 +8,7 @@
  */
 
 // version code in format yymmddb (b = daily build)
-#define VERSION 2305301
+#define VERSION 2306010
 
 //uncomment this if you have a "my_config.h" file you'd like to use
 //#define WLED_USE_MY_CONFIG
@@ -690,9 +690,11 @@ WLED_GLOBAL bool e131NewData _INIT(false);
 WLED_GLOBAL BusManager busses _INIT(BusManager());
 WLED_GLOBAL WS2812FX strip _INIT(WS2812FX());
 WLED_GLOBAL BusConfig* busConfigs[WLED_MAX_BUSSES+WLED_MIN_VIRTUAL_BUSSES] _INIT({nullptr}); //temporary, to remember values from network callback until after
-WLED_GLOBAL bool doInitBusses _INIT(false);
-WLED_GLOBAL bool loadLedmap _INIT(false); //WLEDMM use as bool and use loadedLedmap for Nr
-WLED_GLOBAL uint8_t loadedLedmap _INIT(0); //WLEDMM default 0
+// WLEDMM a few "poor man's" mutal exclusion (mutex) flags, because there are not mutex objects on 8266.
+WLED_GLOBAL volatile bool doInitBusses _INIT(false);        // WLEDMM "volatile" added - needed as we want to sync parallel tasks
+WLED_GLOBAL volatile bool loadLedmap _INIT(false);          // WLEDMM use as bool and use loadedLedmap for Nr
+WLED_GLOBAL volatile uint8_t loadedLedmap _INIT(0);         // WLEDMM default 0
+WLED_GLOBAL volatile bool suspendStripService _INIT(false); // WLEDMM temporarily prevent running strip.service, when strip or segments are "under update" and inconsistent
 #ifndef ESP8266
 WLED_GLOBAL char  *ledmapNames[WLED_MAX_LEDMAPS-1] _INIT_N(({nullptr}));
 #endif