diff --git a/application/basilisk/base/content/browser-addons.js b/application/basilisk/base/content/browser-addons.js
index 2cbb1da864..0740c513fb 100644
--- a/application/basilisk/base/content/browser-addons.js
+++ b/application/basilisk/base/content/browser-addons.js
@@ -334,10 +334,27 @@ const gXPInstallObserver = {
 
         messageString = gNavigatorBundle.getFormattedString(error, args);
 
-        if (install.error == AddonManager.ERROR_CORRUPT_FILE &&
-            install.errorDetail &&
-            typeof install.errorDetail == "string") {
-          messageString += "\n" + "Details: " + install.errorDetail;
+        if (install.error == AddonManager.ERROR_CORRUPT_FILE) {
+          let detail = null;
+          if (install.errorDetail !== undefined && install.errorDetail !== null) {
+            detail = install.errorDetail;
+            if (typeof detail != "string") {
+              if (detail && typeof detail.message == "string" && detail.message) {
+                detail = detail.message;
+              } else {
+                detail = String(detail);
+              }
+            }
+            detail = detail.replace(/[\r\n\t]+/g, " ").trim();
+          }
+
+          let detailString;
+          if (detail) {
+            detailString = gNavigatorBundle.getFormattedString("addonInstallErrorDetail", [detail]);
+          } else {
+            detailString = gNavigatorBundle.getFormattedString("addonInstallErrorDetailCode", [String(install.error)]);
+          }
+          messageString += " " + detailString;
         }
 
         PopupNotifications.show(browser, notificationID, messageString, anchorID,
diff --git a/application/basilisk/locales/en-US/chrome/browser/browser.properties b/application/basilisk/locales/en-US/chrome/browser/browser.properties
index 572c976a19..8f34a10cd9 100644
--- a/application/basilisk/locales/en-US/chrome/browser/browser.properties
+++ b/application/basilisk/locales/en-US/chrome/browser/browser.properties
@@ -93,6 +93,8 @@ addonLocalInstallError-4=%2$S could not be installed because %1$S cannot modify
 addonLocalInstallError-5=This add-on could not be installed because it has not been verified.
 addonLocalInstallError-8=%2$S could not be installed because %1$S does not support Jetpack (SDK) extensions.
 addonLocalInstallError-9=%2$S could not be installed because %1$S does not support WebExtensions.
+addonInstallErrorDetail=Reason: %S
+addonInstallErrorDetailCode=Reason code: %S
 
 
 # LOCALIZATION NOTE (addonInstallErrorIncompatible):
diff --git a/toolkit/mozapps/extensions/internal/XPIProvider.jsm b/toolkit/mozapps/extensions/internal/XPIProvider.jsm
index c2ca8ab8a9..08b6afa528 100644
--- a/toolkit/mozapps/extensions/internal/XPIProvider.jsm
+++ b/toolkit/mozapps/extensions/internal/XPIProvider.jsm
@@ -4926,6 +4926,17 @@ AddonInstall.prototype = {
         logger.warn("Invalid XPI", e);
         this.error = AddonManager.ERROR_CORRUPT_FILE;
       }
+      if (e !== undefined && e !== null) {
+        if (typeof e == "string") {
+          this.errorDetail = e;
+        } else if (e && typeof e.message == "string" && e.message) {
+          this.errorDetail = e.message;
+        } else {
+          this.errorDetail = String(e);
+        }
+      } else {
+        this.errorDetail = null;
+      }
       aCallback(this);
       return;
     }
@@ -4981,6 +4992,7 @@ AddonInstall.prototype = {
       this.removeTemporaryFile();
       this.state = AddonManager.STATE_AVAILABLE;
       this.error = 0;
+      this.errorDetail = null;
       this.progress = 0;
       this.maxProgress = -1;
       this.hash = this.originalHash;
@@ -5870,6 +5882,17 @@ AddonInstall.prototype = {
         recursiveRemove(stagedAddon);
       this.state = AddonManager.STATE_INSTALL_FAILED;
       this.error = AddonManager.ERROR_FILE_ACCESS;
+      if (e !== undefined && e !== null) {
+        if (typeof e == "string") {
+          this.errorDetail = e;
+        } else if (e && typeof e.message == "string" && e.message) {
+          this.errorDetail = e.message;
+        } else {
+          this.errorDetail = String(e);
+        }
+      } else {
+        this.errorDetail = null;
+      }
       XPIProvider.removeActiveInstall(this);
       AddonManagerPrivate.callAddonListeners("onOperationCancelled",
                                              createWrapper(this.addon));
diff --git a/toolkit/mozapps/webextensions/internal/XPIProvider.jsm b/toolkit/mozapps/webextensions/internal/XPIProvider.jsm
index 24ea811ada..2c04522592 100644
--- a/toolkit/mozapps/webextensions/internal/XPIProvider.jsm
+++ b/toolkit/mozapps/webextensions/internal/XPIProvider.jsm
@@ -5735,6 +5735,17 @@ class AddonInstall {
         recursiveRemove(stagedAddon);
       this.state = AddonManager.STATE_INSTALL_FAILED;
       this.error = AddonManager.ERROR_FILE_ACCESS;
+      if (e !== undefined && e !== null) {
+        if (typeof e == "string") {
+          this.errorDetail = e;
+        } else if (e && typeof e.message == "string" && e.message) {
+          this.errorDetail = e.message;
+        } else {
+          this.errorDetail = String(e);
+        }
+      } else {
+        this.errorDetail = null;
+      }
       XPIProvider.removeActiveInstall(this);
       AddonManagerPrivate.callAddonListeners("onOperationCancelled",
                                              this.addon.wrapper);
@@ -5919,6 +5930,17 @@ class LocalAddonInstall extends AddonInstall {
         logger.warn("Invalid XPI", message);
         this.state = AddonManager.STATE_DOWNLOAD_FAILED;
         this.error = error;
+        if (message !== undefined && message !== null) {
+          if (typeof message == "string") {
+            this.errorDetail = message;
+          } else if (message && typeof message.message == "string" && message.message) {
+            this.errorDetail = message.message;
+          } else {
+            this.errorDetail = String(message);
+          }
+        } else {
+          this.errorDetail = null;
+        }
         XPIProvider.removeActiveInstall(this);
         AddonManagerPrivate.callInstallListeners("onNewInstall",
                                                  this.listeners,
@@ -6031,6 +6053,7 @@ class DownloadAddonInstall extends AddonInstall {
       this.removeTemporaryFile();
       this.state = AddonManager.STATE_AVAILABLE;
       this.error = 0;
+      this.errorDetail = null;
       this.progress = 0;
       this.maxProgress = -1;
       this.hash = this.originalHash;
@@ -6102,6 +6125,17 @@ class DownloadAddonInstall extends AddonInstall {
       logger.warn("Failed to start download for addon " + this.sourceURI.spec, e);
       this.state = AddonManager.STATE_DOWNLOAD_FAILED;
       this.error = AddonManager.ERROR_FILE_ACCESS;
+      if (e !== undefined && e !== null) {
+        if (typeof e == "string") {
+          this.errorDetail = e;
+        } else if (e && typeof e.message == "string" && e.message) {
+          this.errorDetail = e.message;
+        } else {
+          this.errorDetail = String(e);
+        }
+      } else {
+        this.errorDetail = null;
+      }
       XPIProvider.removeActiveInstall(this);
       AddonManagerPrivate.callInstallListeners("onDownloadFailed",
                                                this.listeners, this.wrapper);