Added catch for stats of 0 to prevent errors.

module/roll/classes/dg-percentile-roll.js

@@ -255,6 +255,20 @@ export class DGPercentileRoll extends DGRoll {
     return { target, localizedKey, skillPath };
   }
 
+  /**
+   * i18n key for a user-facing warning when this roll must not be made, or null if allowed.
+   * @returns {string|null}
+   */
+  get blockedRollMessage() {
+    if (this.type !== "stat") return null;
+
+    const x5 = Number(this.target);
+    if (!Number.isFinite(x5) || x5 < 1) {
+      return "DG.Roll.CannotRollStat";
+    }
+    return null;
+  }
+
   /**
    * Create label based on result of roll
    *
@@ -392,7 +406,7 @@ export class DGPercentileRoll extends DGRoll {
 
     const { rollTargetModifier } = this;
 
-    if (!this.target || Number.isNaN(this.target)) {
+    if (this.target == null || Number.isNaN(this.target)) {
       return null;
     }
 

module/roll/roll.js

@@ -100,6 +100,11 @@ export async function processDGRoll(event, roll) {
   const shiftKey = event?.shiftKey ?? false;
   const which = event?.which ?? 0;
 
+  if (roll instanceof DGPercentileRoll && roll.blockedRollMessage) {
+    ui.notifications.warn(roll.blockedRollMessage, { localize: true });
+    return;
+  }
+
   if (shiftKey || which === 3) {
     if (!(roll instanceof DGSanityDamageRoll)) {
       const dialogData = await roll.showDialog();

module/sheets/mixins/roll-sheet-mixin.js

@@ -36,8 +36,14 @@ export default function RollSheetMixin(Base) {
      * @private
      */
     static async _onRoll(event, target) {
-      if (target.classList.contains("not-rollable") || event.which === 2)
+      if (event.which === 2) return;
+
+      if (target.classList.contains("not-rollable")) {
+        if (target.dataset.rolltype === "stat") {
+          ui.notifications.warn("DG.Roll.CannotRollStat", { localize: true });
+        }
         return;
+      }
 
       const item = this.actor.items.get(target.dataset.iid);
       const roll = createDGRollFromDataset(target.dataset, {