diff --git a/lifemonitor/api/controllers.py b/lifemonitor/api/controllers.py
index 9b8bb3aad..fea5456ee 100644
--- a/lifemonitor/api/controllers.py
+++ b/lifemonitor/api/controllers.py
@@ -308,6 +308,9 @@ def workflows_post(body, _registry=None, _submitter_id=None):
     except KeyError as e:
         return lm_exceptions.report_problem(400, "Bad Request", extra_info={"exception": str(e)},
                                             detail=messages.input_data_missing)
+    except lm_exceptions.DownloadException as e:
+        return lm_exceptions.report_problem(400, "Bad Request", extra_info={"exception": str(e)},
+                                            detail=messages.invalid_ro_crate)
     except lm_exceptions.NotValidROCrateException as e:
         return lm_exceptions.report_problem(400, "Bad Request", extra_info={"exception": str(e)},
                                             detail=messages.invalid_ro_crate)
diff --git a/lifemonitor/api/models/rocrate.py b/lifemonitor/api/models/rocrate.py
index a7f603931..b7f80fcfb 100644
--- a/lifemonitor/api/models/rocrate.py
+++ b/lifemonitor/api/models/rocrate.py
@@ -27,15 +27,14 @@
 
 import lifemonitor.exceptions as lm_exceptions
 from lifemonitor.api.models import db
-from lifemonitor.auth.models import Resource, HostingService
+from lifemonitor.auth.models import HostingService, Resource
 from lifemonitor.models import JSON
 from lifemonitor.test_metadata import get_roc_suites
-from lifemonitor.utils import download_url, extract_zip
+from lifemonitor.utils import check_resource_exists, download_url, extract_zip
 from sqlalchemy.ext.hybrid import hybrid_property
 
 from rocrate.rocrate import ROCrate as ROCrateHelper
 
-
 # set module level logger
 logger = logging.getLogger(__name__)
 
@@ -65,7 +64,7 @@ def __init__(self, uri, uuid=None, name=None,
 
     @hybrid_property
     def crate_metadata(self):
-        if not self._metadata_loaded:
+        if not self._metadata_loaded and not self._metadata:
             self.load_metadata()
         return self._metadata
 
@@ -115,6 +114,10 @@ def load_metadata(self) -> dict:
         raise lm_exceptions.NotAuthorizedException(detail=f"Not authorized to download {self.uri}", original_errors=errors)
 
     def download(self, target_path: str) -> str:
+        # report if the workflow is not longer available on the origin server
+        if self._metadata and not check_resource_exists(self.uri):
+            raise lm_exceptions.DownloadException(detail=f"Not found: {self.uri}", status=410)
+
         errors = []
         # try either with authorization header and without authorization
         for authorization in self._get_authorizations():
diff --git a/lifemonitor/exceptions.py b/lifemonitor/exceptions.py
index 1cdd523cf..b8ab12d8e 100644
--- a/lifemonitor/exceptions.py
+++ b/lifemonitor/exceptions.py
@@ -133,6 +133,14 @@ def __init__(self, workflow_uuid, workflow_version, detail=None, **kwargs) -> No
             detail=detail, status=409, **kwargs)
 
 
+class DownloadException(LifeMonitorException):
+
+    def __init__(self, detail=None,
+                 type="about:blank", status=500, instance=None, **kwargs):
+        super().__init__(title="Download error",
+                         detail=detail, status=status, **kwargs)
+
+
 class NotValidROCrateException(LifeMonitorException):
 
     def __init__(self, detail="Not valid RO Crate",
diff --git a/lifemonitor/utils.py b/lifemonitor/utils.py
index 152deecda..12f74a68f 100644
--- a/lifemonitor/utils.py
+++ b/lifemonitor/utils.py
@@ -151,6 +151,13 @@ def _download_from_remote(url, output_stream, authorization=None):
                 output_stream.write(chunk)
 
 
+def check_resource_exists(url):
+    r = requests.head(url, verify=False)
+    result = r.status_code == 200
+    logger.debug("Checking if resource %s exists: %r", url, result)
+    return result
+
+
 def download_url(url: str, target_path: str = None, authorization: str = None) -> str:
     if not target_path:
         target_path = tempfile.mktemp()
@@ -166,13 +173,28 @@ def download_url(url: str, target_path: str = None, authorization: str = None) -
             logger.info("Fetched %s of data from %s",
                         sizeof_fmt(os.path.getsize(target_path)),
                         url)
-    except (urllib.error.URLError, requests.exceptions.HTTPError) as e:
-        # requests raised on an exception as we were trying to download.
+    except urllib.error.URLError as e:
+        logger.exception(e)
         raise \
-            lm_exceptions.NotValidROCrateException(
-                details=f"Error downloading RO-crate from {url}",
+            lm_exceptions.DownloadException(
+                detail=f"Error downloading from {url}",
                 status=400,
                 original_error=str(e))
+    except requests.exceptions.HTTPError as e:
+        logger.exception(e)
+        raise \
+            lm_exceptions.DownloadException(
+                detail=f"Error downloading from {url}",
+                status=e.response.status_code,
+                original_error=str(e))
+    except IOError as e:
+        # requests raised on an exception as we were trying to download.
+        logger.exception(e)
+        raise \
+            lm_exceptions.DownloadException(
+                detail=f"Error downloading from {url}",
+                status=500,
+                original_error=str(e))
     return target_path
 
 
diff --git a/specs/api.yaml b/specs/api.yaml
index ce68e8fee..90b80498e 100644
--- a/specs/api.yaml
+++ b/specs/api.yaml
@@ -610,7 +610,6 @@ paths:
         "404":
           $ref: "#/components/responses/NotFound"
 
-
   /workflows/{wf_uuid}/rocrate/{wf_version}/metadata:
     get:
       x-openapi-router-controller: lifemonitor.api.controllers
@@ -630,7 +629,7 @@ paths:
         "200":
           description: |
             RO-Crate JSON metadata for the specified workflow and workflow version.
-            RO-Crate specifcation is available at https://www.researchobject.org/ro-crate/.          
+            RO-Crate specifcation is available at https://www.researchobject.org/ro-crate/.
         "400":
           $ref: "#/components/responses/BadRequest"
         "401":
@@ -666,6 +665,8 @@ paths:
           $ref: "#/components/responses/Forbidden"
         "404":
           $ref: "#/components/responses/NotFound"
+        "500":
+          $ref: "#/components/responses/InternalServerError"
 
   /workflows/{wf_uuid}/suites:
     get:
@@ -1158,6 +1159,13 @@ components:
           schema:
             $ref: "#/components/schemas/Error"
 
+    InternalServerError:
+      description: Internal Server Error
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Error"
+
     WorkflowRegistered:
       description: A new workflow has been registered.
       content:
@@ -1503,16 +1511,19 @@ components:
                   {
                     uuid: "21ac72ec-b9a5-49e0-b5a6-1322b8b54552",
                     version: "0.1",
-                    links: {
-                      origin: "http://webserver:5000/download?file=ro-crate-galaxy-sortchangecase.crate.zip"
-                    },
-                    ro_crate: {
-                      links: {
-                        "download": "https://lm:8000/workflows/123e4567-e89b-12d3-a456-426614174000/rocrate/1.0/download",
-                        "metadata": "https://lm:8000/workflows/123e4567-e89b-12d3-a456-426614174000/rocrate/1.0/metadata",
-                        "origin": "http://webserver:5000/download?file=ro-crate-galaxy-sortchangecase.crate.zip"
-                      }
-                    },
+                    links:
+                      {
+                        origin: "http://webserver:5000/download?file=ro-crate-galaxy-sortchangecase.crate.zip",
+                      },
+                    ro_crate:
+                      {
+                        links:
+                          {
+                            "download": "https://lm:8000/workflows/123e4567-e89b-12d3-a456-426614174000/rocrate/1.0/download",
+                            "metadata": "https://lm:8000/workflows/123e4567-e89b-12d3-a456-426614174000/rocrate/1.0/metadata",
+                            "origin": "http://webserver:5000/download?file=ro-crate-galaxy-sortchangecase.crate.zip",
+                          },
+                      },
                     submitter: { id: 501, username: "lm" },
                   },
                 ]
diff --git a/tests/unit/test_utils.py b/tests/unit/test_utils.py
index 28138e38a..695f050d2 100644
--- a/tests/unit/test_utils.py
+++ b/tests/unit/test_utils.py
@@ -29,6 +29,6 @@
 
 def test_download_url_404():
     with tempfile.TemporaryDirectory() as d:
-        with pytest.raises(lm_exceptions.NotValidROCrateException) as excinfo:
+        with pytest.raises(lm_exceptions.DownloadException) as excinfo:
             _ = utils.download_url('http://httpbin.org/status/404', os.path.join(d, 'get_404'))
-        assert excinfo.value.status == 400
+        assert excinfo.value.status == 404