diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index cb6715e..83b70e7 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -149,5 +149,65 @@
 	"optionsSaveButton": {
 		"message": "Apply",
 		"description": "Name of button in options-page to save changes."
+	},
+
+	"errorPageTitle": {
+		"message": "Shellfox error",
+		"description": "Title of the error-page."
+	},
+
+	"errorTitle": {
+		"message": "Shellfox failed to run command",
+		"description": "Heading-title of the error-page."
+	},
+
+	"errorNotInstalled": {
+		"message": "It seems that Shellfox is not fully installed!",
+		"description": "Summary of not-installed error."
+	},
+
+	"errorNotInstalledDesc": {
+		"message": "Shellfox, unlike most extensions, requires a script to be installed on your computer. This script, <code>shellfox.sh</code>, is what allows us to execute shell commands.It seems that Shellfox is not fully installed!",
+		"description": "Detailed description of not-installed error."
+	},
+
+	"repairInstallTitle": {
+		"message": "Completing installation",
+		"description": "Title of the repair-section for installation."
+	},
+
+	"repairInstallIntro": {
+		"message": "To install Shellfox’es local component:",
+		"description": "Intro to the installation guide, following by an itemized list of steps."
+	},
+
+	"repairInstallStep1": {
+		"message": "Download the script through the repository’s ZIP archive <a id='zip_link'>here</a>.",
+		"description": "Step in the installation guide."
+	},
+
+	"repairInstallStep2": {
+		"message": "Extract the ZIP archive: This leaves a <code>shellfox/</code> folder.",
+		"description": "Step in the installation guide."
+	},
+
+	"repairInstallStep3": {
+		"message": "Open a terminal within that <code>shellfox/</code> folder.",
+		"description": "Step in the installation guide."
+	},
+
+	"repairInstallStep4": {
+		"message": "Run the command, <code>$ sudo make native-install</code>",
+		"description": "Step in the installation guide."
+	},
+
+	"repairInstallStep5": {
+		"message": "You’re done: Party!!",
+		"description": "Light-hearted celebration step in the installation guide."
+	},
+
+	"repairInstallTerminalIntro": {
+		"message": "From a terminal, that would look something like:",
+		"description": "Intro to a terminal-based installation description."
 	}
 }
diff --git a/_locales/eo/messages.json b/_locales/eo/messages.json
index 902eb71..ddfd52a 100644
--- a/_locales/eo/messages.json
+++ b/_locales/eo/messages.json
@@ -1,12 +1,12 @@
 {
 	"extensionName": {
 		"message": "Ŝelvulpo",
-		"description": "Nomo de la aldonaĵo."
+		"description": "Nomo de la etendaĵo."
 	},
 
 	"extensionDescription": {
 		"message": "Ruli ŝel-ordonojn de Firefox, facile.",
-		"description": "Priskribo de la aldonaĵo."
+		"description": "Priskribo de la etendaĵo."
 	},
 
 	"pageActionName": {
@@ -149,5 +149,54 @@
 	"optionsSaveButton": {
 		"message": "Konservi",
 		"description": "Nomo de butono ĉe agordopaĝo por konservi ŝanĝojn."
+	},
+
+	"errorPageTitle": {
+		"message": "Ŝelvulpo eraris"
+	},
+
+	"errorTitle": {
+		"message": "Ŝelvulpo malsukcesis ruli ordonon"
+	},
+
+	"errorNotInstalled": {
+		"message": "Ŝajnas ke Ŝelvulpo ne estas fininstalita!"
+	},
+
+	"errorNotInstalledDesc": {
+		"message": "Ŝelvulpo, malkiel aliaj etendaĵoj, postulas instalon de skripto je via komputilo. Estas tiu skripto, <code>shellfox.sh</code>, kiu povigas la etendaĵon ruli ŝel-ordonojn je via komputilo."
+	},
+
+	"repairInstallTitle": {
+		"message": "Kiel fininstali"
+	},
+
+	"repairInstallIntro": {
+		"message": "Por instali la sisteman skripton Ŝelvulpan:"
+	},
+
+	"repairInstallStep1": {
+		"message": "Elŝutu la skripton per ZIP-arĥivo de la koddeponejo, <a id='zip_link'>de ĉi tie</a>."
+	},
+
+	"repairInstallStep2": {
+		"message": "Elarĥivigu la ZIP-dosieron: Ĉi tio kreos <code>shellfox</code>-dosierujon."
+	},
+
+	"repairInstallStep3": {
+		"message": "Rulu terminalon en la ĵus elarĥivigita dosierujo <code>shellfox/</code>."
+
+	},
+
+	"repairInstallStep4": {
+		"message": "Rulu terminale, <code>$ sudo make native-install</code>"
+	},
+
+	"repairInstallStep5": {
+		"message": "Gratulegon: Vi venkis!!!"
+	},
+
+	"repairInstallTerminalIntro": {
+		"message": "Farita sole en terminalo, aspektus jene:"
 	}
 }
diff --git a/background.js b/background.js
index afd5aff..790057a 100644
--- a/background.js
+++ b/background.js
@@ -6,6 +6,19 @@ function initShellfoxProgram() {
 	port.onDisconnect.addListener((port) => {
 		console.log(port.error);
 		port = undefined;
+
+		// Tell the user about the error…
+		browser.tabs.query({"active": true}).then((tabs) => {
+			let openerTab = undefined;
+			if (tabs && tabs.length > 0)
+				openerTab = tabs[0].id;
+
+			browser.tabs.create({
+				"active": true,
+				"url": "/error.html",
+				"openerTabId": openerTab
+			})
+		});
 	});
 }
 
diff --git a/error.html b/error.html
new file mode 100644
index 0000000..f99225a
--- /dev/null
+++ b/error.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html lang="en">
+	<head>
+		<meta charset="utf8" />
+		<title id="errorPageTitle">Shellfox error</title>
+	</head>
+
+	<body>
+		<h1 id="errorTitle">Shellfox failed to run command</h1>
+		<h2><span class="command"></span></h2>
+
+		<h3 id="notInstalled">It seems that Shellfox is not fully installed!</h3>
+		<p id="notInstalledDesc">Shellfox, unlike most extensions, requires a script to be installed on your computer. This script, <code>shellfox.sh</code>, is what allows us to execute shell commands.</p>
+
+		<h3 id="installTitle">Completing installation</h3>
+		<p id="installIntro">To install Shellfox’es local component:</p>
+		<ol>
+			<li id="installStep1">Download the script through the repository’s ZIP archive <a href="https://hak.xwx.moe/jadedctrl/shellfox/archive/master.zip">here</a>.</li>
+			<li id="installStep2">Extract the ZIP archive: This leaves a <code>shellfox/</code> folder.</li>
+			<li id="installStep3">Open a terminal within that <code>shellfox/</code> folder.</li>
+			<li id="installStep4">Run the command, <code>$ sudo make native-install</code></li>
+			<li id="installStep5">You’re done: Party!!</li>
+		</ol>
+
+		<p id="installTerminalIntro">From a terminal, that would look something like:</p>
+		<code>$ curl https://hak.xwx.moe/jadedctrl/shellfox/archive/master.tar.gz | tar -xzv</code><br>
+		<code>$ cd shellfox/</code><br>
+		<code>$ sudo make native-install</code><br>
+	</body>
+
+	<script src="error.js"></script>
+</html>
diff --git a/error.js b/error.js
new file mode 100644
index 0000000..68e1ec9
--- /dev/null
+++ b/error.js
@@ -0,0 +1,17 @@
+document.getElementsByTagName("html")[0].setAttribute("lang", browser.i18n.getMessage("@@ui_locale"));
+
+document.getElementById("errorPageTitle").innerText = browser.i18n.getMessage("errorPageTitle");
+document.getElementById("errorTitle").innerText = browser.i18n.getMessage("errorTitle");
+document.getElementById("notInstalled").innerText = browser.i18n.getMessage("errorNotInstalled");
+document.getElementById("notInstalledDesc").innerHTML = browser.i18n.getMessage("errorNotInstalledDesc");
+
+document.getElementById("installTitle").innerText = browser.i18n.getMessage("repairInstallTitle");
+document.getElementById("installIntro").innerText = browser.i18n.getMessage("repairInstallIntro");
+document.getElementById("installStep1").innerHTML = browser.i18n.getMessage("repairInstallStep1");
+document.getElementById("installStep2").innerHTML = browser.i18n.getMessage("repairInstallStep2");
+document.getElementById("installStep3").innerHTML = browser.i18n.getMessage("repairInstallStep3");
+document.getElementById("installStep4").innerHTML = browser.i18n.getMessage("repairInstallStep4");
+document.getElementById("installStep5").innerText = browser.i18n.getMessage("repairInstallStep5");
+document.getElementById("installTerminalIntro").innerText = browser.i18n.getMessage("repairInstallTerminalIntro");
+
+document.getElementById("zip_link").setAttribute("href", "https://hak.xwx.moe/jadedctrl/shellfox/archive/master.zip");