diff --git a/src/content.js b/src/content.js
index 6594a32d..e9506a09 100644
--- a/src/content.js
+++ b/src/content.js
@@ -55,6 +55,7 @@ export default class Content {
    * @returns {Content} - the parsed JSON payload to use in requests.
    */
   getContentPayload(config) {
+    const errors = [];
     if (!config.inputs.payload) {
       throw new SlackError(
         config.core,
@@ -71,8 +72,7 @@ export default class Content {
       return /** @type {Content} */ (content);
     } catch (error) {
       if (error instanceof Error) {
-        config.core.debug("Failed to parse input payload as YAML");
-        config.core.debug(error.message);
+        errors.push(error);
       }
     }
     try {
@@ -90,11 +90,12 @@ export default class Content {
       }
       return JSON.parse(trimmed);
     } catch (/** @type {any} */ error) {
+      errors.unshift(error);
       throw new SlackError(
         config.core,
         "Invalid input! Failed to parse contents of the provided payload",
         {
-          cause: error,
+          cause: { values: errors },
         },
       );
     }
@@ -140,7 +141,7 @@ export default class Content {
         config.core,
         "Invalid input! Failed to parse contents of the provided payload file",
         {
-          cause: error,
+          cause: { values: [error] },
         },
       );
     }
diff --git a/src/errors.js b/src/errors.js
index b2d4ce0c..3d0d87b1 100644
--- a/src/errors.js
+++ b/src/errors.js
@@ -1,12 +1,17 @@
 import core from "@actions/core";
 
+/**
+ * @typedef Cause
+ * @property {Error[]} [values] - Caught exceptions.
+ */
+
 /**
  * SlackError is a custom error wrapper for known errors of Slack GitHub Action.
  */
 export default class SlackError extends Error {
   /**
    * @typedef Options
-   * @property {Error} [cause] - thrown exception of this error.
+   * @property {Cause} [cause] - Reason for an error.
    */
 
   /**
diff --git a/src/index.js b/src/index.js
index fcdf2277..ff3b701b 100644
--- a/src/index.js
+++ b/src/index.js
@@ -6,13 +6,21 @@ import send from "./send.js";
  * from the send.js file for testing purposes.
  */
 try {
-  send(core);
+  await send(core);
 } catch (error) {
   if (error instanceof Error) {
     core.error(error.message);
-    core.debug(`${error.name} cause: ${error.cause}`);
-    core.debug(`${error.name} stack: ${error.stack}`);
+    /** @type {import('./errors.js').Cause} */
+    const causes = /** @type {any} */ (error.cause);
+    if (causes?.values) {
+      for (const cause of causes.values) {
+        core.info(`${cause.stack}`);
+      }
+    } else {
+      core.info(`${error.stack}`);
+    }
   } else {
     core.error(`${error}`);
   }
+  throw error;
 }
diff --git a/test/content.spec.js b/test/content.spec.js
index be279d44..30a37286 100644
--- a/test/content.spec.js
+++ b/test/content.spec.js
@@ -1,6 +1,7 @@
 import path from "node:path";
 import core from "@actions/core";
 import { assert } from "chai";
+import { YAMLException } from "js-yaml";
 import Config from "../src/config.js";
 import Content from "../src/content.js";
 import SlackError from "../src/errors.js";
@@ -190,6 +191,11 @@ describe("content", () => {
             err.message,
             "Invalid input! Failed to parse contents of the provided payload",
           );
+          assert.isDefined(err.cause?.values);
+          assert.equal(err.cause.values.length, 2);
+          const [jsonError, yamlError] = err.cause.values;
+          assert.isTrue(jsonError instanceof SyntaxError);
+          assert.isTrue(yamlError instanceof YAMLException);
         } else {
           assert.fail("Failed to throw a SlackError", err);
         }
@@ -334,8 +340,10 @@ describe("content", () => {
             err.message,
             "Invalid input! Failed to parse contents of the provided payload file",
           );
+          assert.isDefined(err.cause?.values);
+          assert.equal(err.cause.values.length, 1);
           assert.include(
-            err.cause.message,
+            err.cause.values[0].message,
             "Invalid input! Failed to parse file extension unknown.md",
           );
         } else {
@@ -343,5 +351,52 @@ describe("content", () => {
         }
       }
     });
+
+    it("fails if invalid JSON exists in the input payload", async () => {
+      mocks.core.getInput.withArgs("payload-file-path").returns("example.json");
+      mocks.fs.readFileSync
+        .withArgs(path.resolve("example.json"), "utf-8")
+        .returns(`{
+            "message": "a truncated file without an end`);
+      try {
+        await send(mocks.core);
+        assert.fail("Failed to throw for invalid JSON");
+      } catch (err) {
+        if (err instanceof SlackError) {
+          assert.include(
+            err.message,
+            "Invalid input! Failed to parse contents of the provided payload file",
+          );
+          assert.isDefined(err.cause?.values);
+          assert.equal(err.cause.values.length, 1);
+          assert.isTrue(err.cause.values[0] instanceof SyntaxError);
+        } else {
+          assert.fail("Failed to throw a SlackError", err);
+        }
+      }
+    });
+
+    it("fails if invalid YAML exists in the input payload", async () => {
+      mocks.core.getInput.withArgs("payload-file-path").returns("example.yaml");
+      mocks.fs.readFileSync
+        .withArgs(path.resolve("example.yaml"), "utf-8")
+        .returns(`- "message": "assigned": "values"`);
+      try {
+        await send(mocks.core);
+        assert.fail("Failed to throw for invalid YAML");
+      } catch (err) {
+        if (err instanceof SlackError) {
+          assert.include(
+            err.message,
+            "Invalid input! Failed to parse contents of the provided payload file",
+          );
+          assert.isDefined(err.cause?.values);
+          assert.equal(err.cause.values.length, 1);
+          assert.isTrue(err.cause.values[0] instanceof YAMLException);
+        } else {
+          assert.fail("Failed to throw a SlackError", err);
+        }
+      }
+    });
   });
 });