diff --git a/resources/drag-and-drop.js b/resources/drag-and-drop.js
index d2c0446..f7e07c3 100644
--- a/resources/drag-and-drop.js
+++ b/resources/drag-and-drop.js
@@ -105,20 +105,35 @@ const FirebaseConfigDropArea = (function () {
     }
 
     #parseAndUpdateInputs(content) {
+      // Remove previous class - default style
+      this.privateKeyFile.removeClass("json-error").removeClass("json-properties-error");
+
       try {
         const data = JSON.parse(content);
+        const clientEmail = data["clientEmail"] || data["client_email"] || "";
+        const privateKey = data["privateKey"] || data["private_key"] || "";
+
+        if (!clientEmail || !privateKey) {
+          RED.notify(`JSON file: '${privateKey ? "Client Email" : "Private Key"}' property missing.`, "error");
+          this.privateKeyFile
+            .addClass("json-properties-error")
+            .html("<p>Please ensure your JSON file contains the <code>clientEmail</code> and <code>privateKey</code> properties.</p>");
+          return;
+        }
 
         $("#node-config-input-clientEmail")
-          .data("data", data["clientEmail"] || data["client_email"])
+          .data("data", clientEmail)
           .val("__PWRD__");
         $("#node-config-input-privateKey")
-          .data("data", (data["privateKey"] || data["private_key"] || "").trim())
+          .data("data", privateKey.trim())
           .val("__PWRD__");
-        $("#node-config-input-projectId").val(data["projectId"] || data["project_id"])
+        $("#node-config-input-projectId")
+          .val(data["projectId"] || data["project_id"])
           .trigger("change"); // No need to trigger everything
+
         this.privateKeyFile.html("The file has been loaded.");
       } catch (error) {
-        this.privateKeyFile.html("An error has occurred :(");
+        this.privateKeyFile.addClass("json-error").html("An error has occurred :(");
         alert(error.message ?? String(error));
       }
     }
diff --git a/resources/styles.css b/resources/styles.css
index 1b856f2..4537d23 100644
--- a/resources/styles.css
+++ b/resources/styles.css
@@ -41,11 +41,12 @@
 
 #json-drop-target {
   cursor: pointer;
+  display: grid;
+  place-items: center;
   margin: auto;
   width: 100%;
   height: 150px;
   text-align: center;
-  line-height: 150px;
   background-color: lightgrey;
   color: darkgray;
   border-color: darkgray;
@@ -57,6 +58,15 @@
   box-shadow: 11px 10px 17px -12px rgba(0, 0, 0, 0.75);
 }
 
+#json-drop-target.json-error {
+  color: var(--red-ui-form-input-border-error-color) !important;
+}
+
+#json-drop-target.json-properties-error {
+  color: var(--red-ui-form-input-border-error-color) !important;
+  font-size: var(--red-ui-primary-font-size);
+}
+
 #file-drop-target {
   position: absolute;
   top: 0;
diff --git a/src/lib/nodes/firebase-client.ts b/src/lib/nodes/firebase-client.ts
index 8a07161..bd9a8d9 100644
--- a/src/lib/nodes/firebase-client.ts
+++ b/src/lib/nodes/firebase-client.ts
@@ -204,26 +204,26 @@ export class FirebaseClient {
 
 		if (Object.keys(content).length === 0) {
 			const { credentials } = this.node;
+
+			// Get the projectId from URL (v < 0.6)
 			const projectId = credentials.url
 				?.split("https://")
 				.pop()
 				?.split(/-default-rtdb\.((asia-southeast1|europe-west1)\.firebasedatabase\.app|firebaseio\.com)(\/)?$/)[0];
 
-			// For line breaks issue
+			// For line breaks issue (v < 0.6)
 			const privateKey = JSON.stringify(credentials.privateKey)
 				?.replace(/\\\\n/gm, "\n")
 				.replaceAll('"', "")
 				.replaceAll("\\", "");
 
-			cred.clientEmail = credentials.clientEmail;
-
 			// The introduction of 'projectId' in the credentials also introduces the change from 'val()' to 'data("data")'
 			// which no longer needs to be stringify to solve the line breaks issue
-			cred.privateKey = privateKey.match("\n") === null ? credentials.privateKey : privateKey;
+			cred.privateKey = privateKey?.match("\n") === null ? credentials.privateKey : privateKey;
 			cred.projectId = credentials.projectId || projectId;
-
-			// For json input (deprecated)
+			cred.clientEmail = credentials.clientEmail;
 		} else {
+			// For json input (deprecated)
 			cred.clientEmail = content.clientEmail || content.client_email;
 			cred.privateKey = content.privateKey || content.private_key;
 			cred.projectId = content.projectId || content.project_id;