diff --git a/index.html b/index.html
index 38e0c9cb..c5c0e87d 100644
--- a/index.html
+++ b/index.html
@@ -6034,7 +6034,7 @@
       </div>
 
       <div id="exportToPngTilesScreen" style="display: none" class="dialog">
-        <p>Map will be split into tiles and downloaded as a single zip file. Avoid saving to big images</p>
+        <p>Map will be split into tiles and downloaded as a single zip file. Avoid saving too large images</p>
         <div data-tip="Number of columns" style="margin-bottom: 0.3em">
           <div class="label">Columns:</div>
           <input
@@ -6042,7 +6042,7 @@
             data-stored="tileCols"
             type="range"
             min="2"
-            max="20"
+            max="26"
             value="8"
             style="width: 10em"
           />
@@ -6055,7 +6055,7 @@
             data-stored="tileRows"
             type="range"
             min="2"
-            max="20"
+            max="26"
             value="8"
             style="width: 10em"
           />
@@ -6078,7 +6078,7 @@
           <div class="label">Total size:</div>
           <div id="tileSize" style="display: inline-block">1000 x 1000 px</div>
         </div>
-        <div id="tileStatus" style="background-color: #33333310; font-style: italic"></div>
+        <div id="tileStatus" style="font-style: italic"></div>
       </div>
 
       <div id="resampleDialog" style="display: none" class="dialog">
@@ -8095,9 +8095,9 @@
     <script defer src="libs/rgbquant.min.js"></script>
     <script defer src="libs/jquery.ui.touch-punch.min.js"></script>
     <script defer src="modules/io/save.js?v=1.96.00"></script>
-    <script defer src="modules/io/load.js?v=1.97.02"></script>
+    <script defer src="modules/io/load.js?v=1.97.04"></script>
     <script defer src="modules/io/cloud.js?v=1.96.00"></script>
-    <script defer src="modules/io/export.js?v=1.96.00"></script>
+    <script defer src="modules/io/export.js?v=1.97.03"></script>
 
     <!-- Web Components -->
     <script defer src="components/fill-box.js"></script>
diff --git a/libs/jquery-ui.css b/libs/jquery-ui.css
index beeb5e58..36d437d5 100644
--- a/libs/jquery-ui.css
+++ b/libs/jquery-ui.css
@@ -313,8 +313,9 @@ body .ui-dialog {
   background-color: inherit;
 }
 .ui-dialog .ui-dialog-titlebar {
-  padding: 0.4em 1em;
-  position: relative;
+  display: flex;
+  padding: 0.4em 0.3em;
+  justify-content: space-evenly;
   font-size: 1.2em;
   min-width: 150px;
 }
@@ -328,9 +329,6 @@ body .ui-dialog {
 }
 
 .ui-dialog .ui-dialog-titlebar button {
-  position: absolute;
-  right: 0.5em;
-  top: 53%;
   padding: 0;
   width: 1.8em;
   height: 1.8em;
@@ -340,14 +338,6 @@ body .ui-dialog {
   border: 1px solid #c5c5c5;
 }
 
-.ui-dialog .ui-dialog-titlebar button.ui-dialog-titlebar-collapse {
-  margin: -1em 2.2em 0 0;
-}
-
-.ui-dialog .ui-dialog-titlebar button.ui-dialog-titlebar-close {
-  margin: -1em 0 0;
-}
-
 .ui-dialog .ui-dialog-titlebar button:active {
   border: 1px solid #5d4651;
   color: #5d4651;
diff --git a/modules/dynamic/auto-update.js b/modules/dynamic/auto-update.js
index a77ddd45..85f623f9 100644
--- a/modules/dynamic/auto-update.js
+++ b/modules/dynamic/auto-update.js
@@ -743,7 +743,7 @@ export function resolveVersionConflicts(version) {
 
     const opacity = terrs.attr("opacity");
     const filter = terrs.attr("filter");
-    const scheme = terrs.attr("scheme");
+    const scheme = terrs.attr("scheme") || "bright";
     const terracing = terrs.attr("terracing");
     const skip = terrs.attr("skip");
     const relax = terrs.attr("relax");
diff --git a/modules/io/export.js b/modules/io/export.js
index 27ecf202..c4742612 100644
--- a/modules/io/export.js
+++ b/modules/io/export.js
@@ -71,70 +71,94 @@ async function exportToJpeg() {
 }
 
 async function exportToPngTiles() {
-  return new Promise(async (resolve, reject) => {
-    // download schema
-    const urlSchema = await getMapURL("tiles", {debug: true, fullMap: true});
-    await import("../../libs/jszip.min.js");
-    const zip = new window.JSZip();
+  const status = byId("tileStatus");
+  status.innerHTML = "Preparing files...";
 
-    const canvas = document.createElement("canvas");
-    const ctx = canvas.getContext("2d");
-    canvas.width = graphWidth;
-    canvas.height = graphHeight;
+  const urlSchema = await getMapURL("tiles", {debug: true, fullMap: true});
+  await import("../../libs/jszip.min.js");
+  const zip = new window.JSZip();
 
-    const imgSchema = new Image();
-    imgSchema.src = urlSchema;
-    imgSchema.onload = function () {
-      ctx.drawImage(imgSchema, 0, 0, canvas.width, canvas.height);
-      canvas.toBlob(blob => zip.file(`fmg_tile_schema.png`, blob));
-    };
+  const canvas = document.createElement("canvas");
+  const ctx = canvas.getContext("2d");
+  canvas.width = graphWidth;
+  canvas.height = graphHeight;
 
-    // download tiles
-    const url = await getMapURL("tiles", {fullMap: true});
-    const tilesX = +document.getElementById("tileColsInput").value;
-    const tilesY = +document.getElementById("tileRowsInput").value;
-    const scale = +document.getElementById("tileScaleInput").value;
+  const imgSchema = new Image();
+  imgSchema.src = urlSchema;
+  await loadImage(imgSchema);
 
-    const tileW = (graphWidth / tilesX) | 0;
-    const tileH = (graphHeight / tilesY) | 0;
-    const tolesTotal = tilesX * tilesY;
+  status.innerHTML = "Drawing schema...";
+  ctx.drawImage(imgSchema, 0, 0, canvas.width, canvas.height);
+  const blob = await canvasToBlob(canvas, "image/png");
+  ctx.clearRect(0, 0, canvas.width, canvas.height);
+  zip.file("schema.png", blob);
 
-    const width = graphWidth * scale;
-    const height = width * (tileH / tileW);
-    canvas.width = width;
-    canvas.height = height;
+  // download tiles
+  const url = await getMapURL("tiles", {fullMap: true});
+  const tilesX = +byId("tileColsInput").value;
+  const tilesY = +byId("tileRowsInput").value;
+  const scale = +byId("tileScaleInput").value;
+  const tolesTotal = tilesX * tilesY;
 
-    let loaded = 0;
-    const img = new Image();
-    img.src = url;
-    img.onload = function () {
-      for (let y = 0, i = 0; y + tileH <= graphHeight; y += tileH) {
-        for (let x = 0; x + tileW <= graphWidth; x += tileW, i++) {
-          ctx.drawImage(img, x, y, tileW, tileH, 0, 0, width, height);
-          const name = `fmg_tile_${i}.png`;
-          canvas.toBlob(blob => {
-            zip.file(name, blob);
-            loaded += 1;
-            if (loaded === tolesTotal) return downloadZip();
-          });
-        }
-      }
-    };
+  const tileW = (graphWidth / tilesX) | 0;
+  const tileH = (graphHeight / tilesY) | 0;
 
-    function downloadZip() {
-      const name = `${getFileName()}.zip`;
-      zip.generateAsync({type: "blob"}).then(blob => {
-        const link = document.createElement("a");
-        link.href = URL.createObjectURL(blob);
-        link.download = name;
-        link.click();
-        link.remove();
+  const width = graphWidth * scale;
+  const height = width * (tileH / tileW);
+  canvas.width = width;
+  canvas.height = height;
 
-        setTimeout(() => URL.revokeObjectURL(link.href), 5000);
-        resolve(true);
-      });
+  const img = new Image();
+  img.src = url;
+  await loadImage(img);
+
+  const alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+  for (let y = 0, row = 0, id = 1; y + tileH <= graphHeight; y += tileH, row++) {
+    const rowName = alphabet[row % alphabet.length];
+
+    for (let x = 0, cell = 1; x + tileW <= graphWidth; x += tileW, cell++, id++) {
+      status.innerHTML = `Drawing tile ${rowName}${cell} (${id} of ${tolesTotal})...`;
+      ctx.drawImage(img, x, y, tileW, tileH, 0, 0, width, height);
+      const blob = await canvasToBlob(canvas, "image/png");
+      ctx.clearRect(0, 0, canvas.width, canvas.height);
+      zip.file(`${rowName}${cell}.png`, blob);
     }
+  }
+
+  status.innerHTML = "Zipping files...";
+  zip.generateAsync({type: "blob"}).then(blob => {
+    status.innerHTML = "Downloading the archive...";
+    const link = document.createElement("a");
+    link.href = URL.createObjectURL(blob);
+    link.download = getFileName() + ".zip";
+    link.click();
+    link.remove();
+
+    status.innerHTML = 'Done. Check .zip file in "Downloads" (crtl + J)';
+    setTimeout(() => URL.revokeObjectURL(link.href), 5000);
   });
+
+  // promisified img.onload
+  function loadImage(img) {
+    return new Promise((resolve, reject) => {
+      img.onload = () => resolve();
+      img.onerror = err => reject(err);
+    });
+  }
+
+  // promisified canvas.toBlob
+  function canvasToBlob(canvas, mimeType, qualityArgument = 1) {
+    return new Promise((resolve, reject) => {
+      canvas.toBlob(
+        blob => {
+          if (blob) resolve(blob);
+          else reject(new Error("Canvas toBlob() error"));
+        },
+        mimeType,
+        qualityArgument
+      );
+    });
+  }
 }
 
 // parse map svg to object url
@@ -148,14 +172,14 @@ async function getMapURL(type, options) {
     fullMap = false
   } = options || {};
 
-  const cloneEl = document.getElementById("map").cloneNode(true); // clone svg
+  const cloneEl = byId("map").cloneNode(true); // clone svg
   cloneEl.id = "fantasyMap";
   document.body.appendChild(cloneEl);
   const clone = d3.select(cloneEl);
   if (!debug) clone.select("#debug")?.remove();
 
   const cloneDefs = cloneEl.getElementsByTagName("defs")[0];
-  const svgDefs = document.getElementById("defElements");
+  const svgDefs = byId("defElements");
 
   const isFirefox = navigator.userAgent.toLowerCase().indexOf("firefox") > -1;
   if (isFirefox && type === "mesh") clone.select("#oceanPattern")?.remove();
@@ -218,7 +242,7 @@ async function getMapURL(type, options) {
       .forEach(el => {
         const href = el.getAttribute("href") || el.getAttribute("xlink:href");
         if (!href) return;
-        const emblem = document.getElementById(href.slice(1));
+        const emblem = byId(href.slice(1));
         if (emblem) cloneDefs.append(emblem.cloneNode(true));
       });
   } else {
diff --git a/modules/io/load.js b/modules/io/load.js
index c038eb5c..ff6b2731 100644
--- a/modules/io/load.js
+++ b/modules/io/load.js
@@ -456,16 +456,16 @@ async function parseLoadedData(data, mapVersion) {
     {
       // dynamically import and run auto-update script
       const versionNumber = parseFloat(params[0]);
-      const {resolveVersionConflicts} = await import("../dynamic/auto-update.js?v=1.97.00");
+      const {resolveVersionConflicts} = await import("../dynamic/auto-update.js?v=1.97.04");
       resolveVersionConflicts(versionNumber);
     }
 
     // add custom heightmap color scheme if any
     if (heightmapColorSchemes) {
-      const oceanScheme = terrs.select("#oceanHeights").attr("scheme");
-      const landScheme = terrs.select("#landHeights").attr("scheme");
-      if (!(oceanScheme in heightmapColorSchemes)) addCustomColorScheme(oceanScheme);
-      if (!(landScheme in heightmapColorSchemes)) addCustomColorScheme(landScheme);
+      const oceanScheme = byId("oceanHeights")?.getAttribute("scheme");
+      if (oceanScheme && !(oceanScheme in heightmapColorSchemes)) addCustomColorScheme(oceanScheme);
+      const landScheme = byId("#landHeights")?.getAttribute("scheme");
+      if (landScheme && !(landScheme in heightmapColorSchemes)) addCustomColorScheme(landScheme);
     }
 
     {
diff --git a/modules/ui/options.js b/modules/ui/options.js
index 8442bac5..2f14d9d7 100644
--- a/modules/ui/options.js
+++ b/modules/ui/options.js
@@ -867,11 +867,9 @@ byId("mapToLoad").addEventListener("change", function () {
 });
 
 function openExportToPngTiles() {
+  byId("tileStatus").innerHTML = "";
   closeDialogs();
   updateTilesOptions();
-  const status = byId("tileStatus");
-  status.innerHTML = "";
-  let loading = null;
 
   const inputs = byId("exportToPngTilesScreen").querySelectorAll("input");
   inputs.forEach(input => input.addEventListener("input", updateTilesOptions));
@@ -881,16 +879,7 @@ function openExportToPngTiles() {
     title: "Download tiles",
     width: "23em",
     buttons: {
-      Download: function () {
-        status.innerHTML = "Preparing for download...";
-        setTimeout(() => (status.innerHTML = "Downloading. It may take some time."), 1000);
-        loading = setInterval(() => (status.innerHTML += "."), 1000);
-        exportToPngTiles().then(() => {
-          clearInterval(loading);
-          status.innerHTML = /* html */ `Done. Check file in "Downloads" (crtl + J)`;
-          setTimeout(() => (status.innerHTML = ""), 8000);
-        });
-      },
+      Download: () => exportToPngTiles(),
       Cancel: function () {
         $(this).dialog("close");
       }
@@ -898,7 +887,6 @@ function openExportToPngTiles() {
     close: () => {
       inputs.forEach(input => input.removeEventListener("input", updateTilesOptions));
       debug.selectAll("*").remove();
-      clearInterval(loading);
     }
   });
 }
@@ -928,18 +916,22 @@ function updateTilesOptions() {
   const labels = [];
   const tileW = (graphWidth / tilesX) | 0;
   const tileH = (graphHeight / tilesY) | 0;
-  for (let y = 0, i = 0; y + tileH <= graphHeight; y += tileH) {
-    for (let x = 0; x + tileW <= graphWidth; x += tileW, i++) {
+
+  const alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+  for (let y = 0, row = 0; y + tileH <= graphHeight; y += tileH, row++) {
+    for (let x = 0, column = 1; x + tileW <= graphWidth; x += tileW, column++) {
       rects.push(`<rect x=${x} y=${y} width=${tileW} height=${tileH} />`);
-      labels.push(`<text x=${x + tileW / 2} y=${y + tileH / 2}>${i}</text>`);
+      const label = alphabet[row % alphabet.length] + column;
+      labels.push(`<text x=${x + tileW / 2} y=${y + tileH / 2}>${label}</text>`);
     }
   }
-  const rectsG = "<g fill='none' stroke='#000'>" + rects.join("") + "</g>";
-  const labelsG =
-    "<g fill='#000' stroke='none' text-anchor='middle' dominant-baseline='central' font-size='24px'>" +
-    labels.join("") +
-    "</g>";
-  debug.html(rectsG + labelsG);
+
+  debug.html(`
+    <g fill='none' stroke='#000'>${rects.join("")}</g>
+    <g fill='#000' stroke='none' text-anchor='middle' dominant-baseline='central' font-size='18px'>${labels.join(
+      ""
+    )}</g>
+  `);
 }
 
 // View mode