diff --git a/browser/components/contentanalysis/content/ContentAnalysis.sys.mjs b/browser/components/contentanalysis/content/ContentAnalysis.sys.mjs
index c63c460a2dd4..7bae13531096 100644
--- a/browser/components/contentanalysis/content/ContentAnalysis.sys.mjs
+++ b/browser/components/contentanalysis/content/ContentAnalysis.sys.mjs
@@ -352,8 +352,8 @@ export const ContentAnalysis = {
           windowAndResourceNameOrOperationType.resourceNameOrOperationType
             ?.operationType === Ci.nsIContentAnalysisRequest.eDownload
         ) {
-          // Don't show warn/block dialogs for downloads; they're shown inside
-          // the downloads panel.
+          // Don't show warn/block/error dialogs for downloads; they're shown
+          // inside the downloads panel.
           return;
         }
         const responseResult =
@@ -744,10 +744,7 @@ export const ContentAnalysis = {
   _getErrorDialogMessage(aResourceNameOrOperationType) {
     if (aResourceNameOrOperationType.name) {
       return this.l10n.formatValueSync(
-        aResourceNameOrOperationType.operationType ==
-          Ci.nsIContentAnalysisRequest.eUpload
-          ? "contentanalysis-error-message-upload-file"
-          : "contentanalysis-error-message-download-file",
+        "contentanalysis-error-message-upload-file",
         { filename: aResourceNameOrOperationType.name }
       );
     }
diff --git a/browser/components/downloads/DownloadsCommon.sys.mjs b/browser/components/downloads/DownloadsCommon.sys.mjs
index 4679d650f848..2a56c1131588 100644
--- a/browser/components/downloads/DownloadsCommon.sys.mjs
+++ b/browser/components/downloads/DownloadsCommon.sys.mjs
@@ -75,6 +75,10 @@ const kDownloadsFluentStrings = new Localization(
 );
 
 const kDownloadsStringsRequiringFormatting = {
+  contentAnalysisNoAgentError: true,
+  contentAnalysisInvalidAgentSignatureError: true,
+  contentAnalysisUnspecifiedError: true,
+  contentAnalysisTimeoutError: true,
   sizeWithUnits: true,
   statusSeparator: true,
   statusSeparatorBeforeNumber: true,
diff --git a/browser/components/downloads/DownloadsViewUI.sys.mjs b/browser/components/downloads/DownloadsViewUI.sys.mjs
index 09a8d41feca8..408c25f5d62e 100644
--- a/browser/components/downloads/DownloadsViewUI.sys.mjs
+++ b/browser/components/downloads/DownloadsViewUI.sys.mjs
@@ -34,6 +34,13 @@ XPCOMUtils.defineLazyServiceGetter(
   Ci.nsIApplicationReputationService
 );
 
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "contentAnalysisAgentName",
+  "browser.contentanalysis.agent_name",
+  "A DLP agent"
+);
+
 import { Integration } from "resource://gre/modules/Integration.sys.mjs";
 
 Integration.downloads.defineESModuleGetter(
@@ -877,6 +884,31 @@ DownloadsViewUI.DownloadElementShell.prototype = {
     }
   },
 
+  getContentAnalysisErrorTitle(strings, cancelError) {
+    switch (cancelError) {
+      case Ci.nsIContentAnalysisResponse.eNoAgent:
+        return strings.contentAnalysisNoAgentError(
+          lazy.contentAnalysisAgentName
+        );
+      case Ci.nsIContentAnalysisResponse.eInvalidAgentSignature:
+        return strings.contentAnalysisInvalidAgentSignatureError(
+          lazy.contentAnalysisAgentName
+        );
+      case Ci.nsIContentAnalysisResponse.eTimeout:
+        return strings.contentAnalysisTimeoutError(
+          lazy.contentAnalysisAgentName
+        );
+      case Ci.nsIContentAnalysisResponse.eErrorOther:
+        return strings.contentAnalysisUnspecifiedError(
+          lazy.contentAnalysisAgentName
+        );
+      default:
+        // This also handles the case when cancelError is undefined
+        // because the request wasn't cancelled at all.
+        return strings.blockedByContentAnalysis;
+    }
+  },
+
   /**
    * Returns [title, [details1, details2]] for blocked downloads.
    * The title or details could be raw strings or l10n objects.
@@ -926,7 +958,10 @@ DownloadsViewUI.DownloadElementShell.prototype = {
           break;
         }
         return [
-          s.blockedByContentAnalysis,
+          this.getContentAnalysisErrorTitle(
+            s,
+            this.download.error.contentAnalysisCancelError
+          ),
           [s.unblockContentAnalysis1, s.unblockContentAnalysis2],
         ];
       case lazy.Downloads.Error.BLOCK_VERDICT_DOWNLOAD_SPAM: {
diff --git a/browser/locales/en-US/chrome/browser/downloads/downloads.properties b/browser/locales/en-US/chrome/browser/downloads/downloads.properties
index 5c7d4390eb17..7ebbfe04a823 100644
--- a/browser/locales/en-US/chrome/browser/downloads/downloads.properties
+++ b/browser/locales/en-US/chrome/browser/downloads/downloads.properties
@@ -35,6 +35,13 @@ blockedPotentiallyUnwanted=This file may harm your computer.
 blockedPotentiallyInsecure=File not downloaded: Potential security risk.
 blockedUncommon2=This file is not commonly downloaded.
 blockedByContentAnalysis=This file was blocked by your organization.
+# LOCALIZATION NOTE (contentAnalysisNoAgentError, contentAnalysisInvalidAgentSignatureError,
+#                    contentAnalysisUnspecifiedError, contentAnalysisTimeoutError):
+# %1$S is replaced with the name of the DLP agent.
+contentAnalysisNoAgentError=File was blocked because %1$S is not reachable.
+contentAnalysisInvalidAgentSignatureError=File was blocked because %1$S failed signature verification.
+contentAnalysisUnspecifiedError=File was blocked because of an error in communicating with %1$S.
+contentAnalysisTimeoutError=%1$S timed out, so this file was blocked.
 warnedByContentAnalysis=This download may be unsafe and requires confirmation.
 
 # LOCALIZATION NOTE (fileMovedOrMissing):
diff --git a/toolkit/components/downloads/DownloadCore.sys.mjs b/toolkit/components/downloads/DownloadCore.sys.mjs
index 0fa3a3810232..c20530076f60 100644
--- a/toolkit/components/downloads/DownloadCore.sys.mjs
+++ b/toolkit/components/downloads/DownloadCore.sys.mjs
@@ -1936,6 +1936,7 @@ export var DownloadError = function (aProperties) {
   } else if (aProperties.becauseBlockedByContentAnalysis) {
     this.becauseBlocked = true;
     this.becauseBlockedByContentAnalysis = true;
+    this.contentAnalysisCancelError = aProperties.contentAnalysisCancelError;
     this.contentAnalysisWarnRequestToken =
       aProperties.contentAnalysisWarnRequestToken;
     this.reputationCheckVerdict = aProperties.reputationCheckVerdict;
@@ -2001,6 +2002,12 @@ DownloadError.prototype = {
    */
   becauseBlockedByContentAnalysis: false,
 
+  /**
+   * The cancelError returned by the content analysis tool, which corresponds
+   * to the nsIContentAnalysisResponse.CancelError enum. May be undefined.
+   */
+  contentAnalysisCancelError: undefined,
+
   /**
    * If becauseBlockedByReputationCheck is true, indicates the detailed reason
    * why the download was blocked, according to the "BLOCK_VERDICT_" constants.
@@ -2063,7 +2070,8 @@ DownloadError.fromSerializable = function (aSerializable) {
       property != "becauseBlockedByParentalControls" &&
       property != "becauseBlockedByReputationCheck" &&
       property != "becauseBlockedByContentAnalysis" &&
-      property != "reputationCheckVerdict"
+      property != "reputationCheckVerdict" &&
+      property != "contentAnalysisCancelError"
   );
 
   return e;
@@ -2760,6 +2768,8 @@ DownloadCopySaver.prototype = {
         throw new DownloadError({
           becauseBlockedByContentAnalysis: true,
           reputationCheckVerdict: downloadErrorVerdict,
+          contentAnalysisCancelError:
+            permissionResult.contentAnalysisCancelError,
           contentAnalysisWarnRequestToken:
             permissionResult.contentAnalysisWarnRequestToken,
         });
diff --git a/toolkit/components/downloads/DownloadHistory.sys.mjs b/toolkit/components/downloads/DownloadHistory.sys.mjs
index 6b381d65efde..95f38fe44081 100644
--- a/toolkit/components/downloads/DownloadHistory.sys.mjs
+++ b/toolkit/components/downloads/DownloadHistory.sys.mjs
@@ -151,6 +151,10 @@ export let DownloadHistory = {
     if (download.error && download.error.reputationCheckVerdict) {
       metaData.reputationCheckVerdict = download.error.reputationCheckVerdict;
     }
+    if (download?.error?.hasOwnProperty("contentAnalysisCancelError")) {
+      metaData.contentAnalysisCancelError =
+        download.error.contentAnalysisCancelError;
+    }
 
     // This should be executed before any async parts, to ensure the cache is
     // updated before any notifications are activated.
@@ -444,6 +448,7 @@ class HistoryDownload {
       } else if (metaData.state == METADATA_STATE_BLOCKED_CONTENT_ANALYSIS) {
         this.error = {
           becauseBlockedByContentAnalysis: true,
+          contentAnalysisCancelError: metaData.contentAnalysisCancelError,
           reputationCheckVerdict: metaData.reputationCheckVerdict || "",
         };
       } else if (metaData.state == METADATA_STATE_DIRTY) {
diff --git a/toolkit/components/downloads/DownloadIntegration.sys.mjs b/toolkit/components/downloads/DownloadIntegration.sys.mjs
index 5e9f40ba67e2..47bfad83758f 100644
--- a/toolkit/components/downloads/DownloadIntegration.sys.mjs
+++ b/toolkit/components/downloads/DownloadIntegration.sys.mjs
@@ -552,11 +552,16 @@ export var DownloadIntegration = {
         /* autoAcknowledge*/ true
       )
       .then(response => {
+        let cancelError;
+        if (response?.action === Ci.nsIContentAnalysisResponse.eCanceled) {
+          cancelError = response.cancelError;
+        }
         return {
           verdict: response.shouldAllowContent
             ? Ci.nsIApplicationReputationService.VERDICT_SAFE
             : Ci.nsIApplicationReputationService.VERDICT_DANGEROUS,
           shouldBlock: !response.shouldAllowContent,
+          contentAnalysisCancelError: cancelError,
           contentAnalysisWarnRequestToken: undefined,
         };
       });