diff --git a/lib/private/Files/Storage/DAV.php b/lib/private/Files/Storage/DAV.php
index 786680317668..af32d11bc998 100644
--- a/lib/private/Files/Storage/DAV.php
+++ b/lib/private/Files/Storage/DAV.php
@@ -47,7 +47,6 @@
 use OCP\Files\StorageNotAvailableException;
 use OCP\Util;
 use Sabre\DAV\Client;
-use Sabre\DAV\Exception\NotFound;
 use Sabre\DAV\Xml\Property\ResourceType;
 use Sabre\HTTP\ClientException;
 use Sabre\HTTP\ClientHttpException;
@@ -207,7 +206,9 @@ public function opendir($path) {
 				[],
 				1
 			);
-			$id = md5('webdav' . $this->root . $path);
+			if ($response === false) {
+				return false;
+			}
 			$content = [];
 			$files = array_keys($response);
 			array_shift($files); //the first entry is the current directory
@@ -225,13 +226,6 @@ public function opendir($path) {
 				$content[] = $file;
 			}
 			return IteratorDirectory::wrap($content);
-		} catch (ClientHttpException $e) {
-			if ($e->getHttpStatus() === 404) {
-				$this->statCache->clear($path . '/');
-				$this->statCache->set($path, false);
-				return false;
-			}
-			$this->convertException($e, $path);
 		} catch (\Exception $e) {
 			$this->convertException($e, $path);
 		}
@@ -248,15 +242,11 @@ public function opendir($path) {
 	 *
 	 * @return array propfind response
 	 *
-	 * @throws NotFound
+	 * @throws ClientHttpException
 	 */
 	protected function propfind($path) {
 		$path = $this->cleanPath($path);
 		$cachedResponse = $this->statCache->get($path);
-		if ($cachedResponse === false) {
-			// we know it didn't exist
-			throw new NotFound();
-		}
 		// we either don't know it, or we know it exists but need more details
 		if (is_null($cachedResponse) || $cachedResponse === true) {
 			$this->init();
@@ -274,11 +264,15 @@ protected function propfind($path) {
 					]
 				);
 				$this->statCache->set($path, $response);
-			} catch (NotFound $e) {
-				// remember that this path did not exist
-				$this->statCache->clear($path . '/');
-				$this->statCache->set($path, false);
-				throw $e;
+			} catch (ClientHttpException $e) {
+				if ($e->getHttpStatus() === 404) {
+					$this->statCache->clear($path . '/');
+					$this->statCache->set($path, false);
+					return false;
+				}
+				$this->convertException($e, $path);
+			} catch (\Exception $e) {
+				$this->convertException($e, $path);
 			}
 		} else {
 			$response = $cachedResponse;
@@ -290,17 +284,15 @@ protected function propfind($path) {
 	public function filetype($path) {
 		try {
 			$response = $this->propfind($path);
+			if ($response === false) {
+				return false;
+			}
 			$responseType = [];
 			if (isset($response["{DAV:}resourcetype"])) {
 				/** @var ResourceType[] $response */
 				$responseType = $response["{DAV:}resourcetype"]->getValue();
 			}
 			return (count($responseType) > 0 and $responseType[0] == "{DAV:}collection") ? 'dir' : 'file';
-		} catch (ClientHttpException $e) {
-			if ($e->getHttpStatus() === 404) {
-				return false;
-			}
-			$this->convertException($e, $path);
 		} catch (\Exception $e) {
 			$this->convertException($e, $path);
 		}
@@ -319,13 +311,7 @@ public function file_exists($path) {
 				return true;
 			}
 			// need to get from server
-			$this->propfind($path);
-			return true; //no 404 exception
-		} catch (ClientHttpException $e) {
-			if ($e->getHttpStatus() === 404) {
-				return false;
-			}
-			$this->convertException($e, $path);
+			return ($this->propfind($path) !== false);
 		} catch (\Exception $e) {
 			$this->convertException($e, $path);
 		}
@@ -431,6 +417,9 @@ public function free_space($path) {
 		try {
 			// TODO: cacheable ?
 			$response = $this->client->propfind($this->encodePath($path), ['{DAV:}quota-available-bytes']);
+			if ($response === false) {
+				return FileInfo::SPACE_UNKNOWN;
+			}
 			if (isset($response['{DAV:}quota-available-bytes'])) {
 				return (int)$response['{DAV:}quota-available-bytes'];
 			} else {
@@ -456,6 +445,9 @@ public function touch($path, $mtime = null) {
 				$this->client->proppatch($this->encodePath($path), ['{DAV:}lastmodified' => $mtime]);
 				// non-owncloud clients might not have accepted the property, need to recheck it
 				$response = $this->client->propfind($this->encodePath($path), ['{DAV:}getlastmodified'], 0);
+				if ($response === false) {
+					return false;
+				}
 				if (isset($response['{DAV:}getlastmodified'])) {
 					$remoteMtime = strtotime($response['{DAV:}getlastmodified']);
 					if ($remoteMtime !== $mtime) {
@@ -578,15 +570,13 @@ public function copy($path1, $path2) {
 	public function stat($path) {
 		try {
 			$response = $this->propfind($path);
+			if ($response === false) {
+				return [];
+			}
 			return [
 				'mtime' => strtotime($response['{DAV:}getlastmodified']),
 				'size' => (int)isset($response['{DAV:}getcontentlength']) ? $response['{DAV:}getcontentlength'] : 0,
 			];
-		} catch (ClientHttpException $e) {
-			if ($e->getHttpStatus() === 404) {
-				return [];
-			}
-			$this->convertException($e, $path);
 		} catch (\Exception $e) {
 			$this->convertException($e, $path);
 		}
@@ -597,6 +587,9 @@ public function stat($path) {
 	public function getMimeType($path) {
 		try {
 			$response = $this->propfind($path);
+			if ($response === false) {
+				return false;
+			}
 			$responseType = [];
 			if (isset($response["{DAV:}resourcetype"])) {
 				/** @var ResourceType[] $response */
@@ -610,11 +603,6 @@ public function getMimeType($path) {
 			} else {
 				return false;
 			}
-		} catch (ClientHttpException $e) {
-			if ($e->getHttpStatus() === 404) {
-				return false;
-			}
-			$this->convertException($e, $path);
 		} catch (\Exception $e) {
 			$this->convertException($e, $path);
 		}
@@ -705,6 +693,9 @@ public function getPermissions($path) {
 		$this->init();
 		$path = $this->cleanPath($path);
 		$response = $this->propfind($path);
+		if ($response === false) {
+			return 0;
+		}
 		if (isset($response['{http://owncloud.org/ns}permissions'])) {
 			return $this->parsePermissions($response['{http://owncloud.org/ns}permissions']);
 		} else if ($this->is_dir($path)) {
@@ -721,6 +712,9 @@ public function getETag($path) {
 		$this->init();
 		$path = $this->cleanPath($path);
 		$response = $this->propfind($path);
+		if ($response === false) {
+			return null;
+		}
 		if (isset($response['{DAV:}getetag'])) {
 			return trim($response['{DAV:}getetag'], '"');
 		}
@@ -764,6 +758,13 @@ public function hasUpdated($path, $time) {
 			// force refresh for $path
 			$this->statCache->remove($path);
 			$response = $this->propfind($path);
+			if ($response === false) {
+				if ($path === '') {
+					// if root is gone it means the storage is not available
+					throw new StorageNotAvailableException(get_class($e) . ': ' . $e->getMessage());
+				}
+				return false;
+			}
 			if (isset($response['{DAV:}getetag'])) {
 				$cachedData = $this->getCache()->get($path);
 				$etag = null;
@@ -786,7 +787,7 @@ public function hasUpdated($path, $time) {
 				return $remoteMtime > $time;
 			}
 		} catch (ClientHttpException $e) {
-			if ($e->getHttpStatus() === 404 || $e->getHttpStatus() === 405) {
+			if ($e->getHttpStatus() === 405) {
 				if ($path === '') {
 					// if root is gone it means the storage is not available
 					throw new StorageNotAvailableException(get_class($e) . ': ' . $e->getMessage());