diff --git a/install.ps1 b/install.ps1
index 3f72df34..93d06c52 100644
--- a/install.ps1
+++ b/install.ps1
@@ -8,7 +8,7 @@ param(
 
 $ErrorActionPreference = "Stop"
 $defaultInstallUrl = "https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-$defaultInstallSha256 = "bf522ef64ecbefc14202a879b6c943e44939dfda37eb416b1897070ad7cefa85"
+$defaultInstallSha256 = "d35dc1707a5f5d65fb614f45ed71f47e20e9ffcb4b28470e757cc66533c91ef2"
 $maximumInstallerBytes = 2MB
 $installerExit = 0
 $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }
diff --git a/install.py b/install.py
index 2f923d4d..d98c32be 100644
--- a/install.py
+++ b/install.py
@@ -1878,6 +1878,22 @@ def fetch_manifest(plat: str) -> dict:
     except ValueError as exc:
         print(f"  The file list for {plat} is not valid: {exc}", file=sys.stderr)
         sys.exit(1)
+    except urllib.error.HTTPError as exc:
+        if exc.code == 404:
+            # Asked once, a 4xx being final; the name was checked before any
+            # request, so the revision is what has no such list.
+            print(f"  No file list for {plat} at {RELEASE_REF}.", file=sys.stderr)
+            if RELEASE_REF != DEFAULT_RELEASE_REF:
+                print(f"  RETROBIOS_REF={RELEASE_REF} names a tag that does not exist or "
+                      f"predates {plat}: unset RETROBIOS_REF, or pick a tag from "
+                      "https://github.com/Abdess/retrobios/releases.", file=sys.stderr)
+            else:
+                print("  The repository may be moving its files: run the same command "
+                      "again in a few minutes.", file=sys.stderr)
+            sys.exit(1)
+        print(f"  Could not fetch the file list for {plat}: HTTP {exc.code}", file=sys.stderr)
+        print(NETWORK_ADVICE, file=sys.stderr)
+        sys.exit(1)
     except (urllib.error.URLError, OSError) as exc:
         print(f"  Could not fetch the file list for {plat} after {MAX_RETRIES} "
               f"attempts: {getattr(exc, 'reason', None) or exc}", file=sys.stderr)
diff --git a/install.sh b/install.sh
index 8958d351..141ff853 100755
--- a/install.sh
+++ b/install.sh
@@ -18,7 +18,7 @@ esac
 TEMP_INSTALLER=""
 TEMP_DIRECTORY=""
 DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-DEFAULT_INSTALL_SHA256="bf522ef64ecbefc14202a879b6c943e44939dfda37eb416b1897070ad7cefa85"
+DEFAULT_INSTALL_SHA256="d35dc1707a5f5d65fb614f45ed71f47e20e9ffcb4b28470e757cc66533c91ef2"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {
diff --git a/tests/test_install.py b/tests/test_install.py
index baac8bbb..195bf215 100644
--- a/tests/test_install.py
+++ b/tests/test_install.py
@@ -2841,5 +2841,30 @@ class SteamRetroArchOnMacIsPortable(unittest.TestCase):
             self.assertEqual(install._macos_retroarch_base(), support / "RetroArch")
 
 
+class AMissingFileListNamesTheRef(unittest.TestCase):
+    """A 404 on the manifest said three attempts were made and to check the
+    connection and proxy; it was asked once, and the cause is the ref."""
+
+    def _run(self, ref: str) -> str:
+        error = install.urllib.error.HTTPError("u", 404, "Not Found", None, None)
+        with unittest.mock.patch.object(install, "RELEASE_REF", ref), \
+                unittest.mock.patch.object(install, "_fetch_json", side_effect=error), \
+                contextlib.redirect_stderr(io.StringIO()) as err, \
+                self.assertRaises(SystemExit):
+            install.fetch_manifest("retroarch")
+        return err.getvalue()
+
+    def test_a_pinned_tag_is_named(self):
+        text = self._run("v2020.01.01")
+        self.assertIn("RETROBIOS_REF=v2020.01.01", text)
+        self.assertNotIn("attempts", text)
+        self.assertNotIn("proxy", text)
+
+    def test_the_default_ref_is_not_blamed_on_the_network(self):
+        text = self._run(install.DEFAULT_RELEASE_REF)
+        self.assertIn("No file list for retroarch", text)
+        self.assertNotIn("proxy", text)
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/wiki/troubleshooting.md b/wiki/troubleshooting.md
index c908a37e..a263c8d6 100644
--- a/wiki/troubleshooting.md
+++ b/wiki/troubleshooting.md
@@ -264,13 +264,16 @@ python install.py --platform retroarch --dest ~/RetroArch/system/
 python install.py --platform batocera --dest /userdata/bios/
 ```
 
-Use `python install.py --help` to see all available platforms and options.
+`python install.py --list-platforms` lists the platforms the installer knows
+and the ones it detects here; `--help` lists the options.
 
 **Manifest or file not found:**
 
 The one-line bootstrap verifies the downloaded installer before running it, and
-the installer reads its manifests from the same revision. A 404 usually means
-the platform name is wrong; check `python install.py --list-platforms`.
+the installer reads its manifests from the same revision. A platform name is
+checked before anything is downloaded, so a "No file list" message comes from
+the revision: `RETROBIOS_REF` naming a tag that does not exist, or one older
+than the platform. Unset it, or pick a tag from the releases page.
 `RETROBIOS_REF` pins an installation to a published tag when a reproducible
 file set matters more than the newest one.