diff --git a/common/ASC.Data.Storage/PathUtils.cs b/common/ASC.Data.Storage/PathUtils.cs
index 9b7deb7738..6291a3e477 100644
--- a/common/ASC.Data.Storage/PathUtils.cs
+++ b/common/ASC.Data.Storage/PathUtils.cs
@@ -83,7 +83,7 @@ namespace ASC.Data.Storage
                 virtPath = "";
             }
 
-            if (virtPath.StartsWith("~") && !Uri.IsWellFormedUriString(virtPath, UriKind.Absolute))
+            if (virtPath.StartsWith('~') && !Uri.IsWellFormedUriString(virtPath, UriKind.Absolute))
             {
                 var rootPath = "/";
                 if (!string.IsNullOrEmpty(WebHostEnvironment?.WebRootPath) && WebHostEnvironment?.WebRootPath.Length > 1)
diff --git a/web/ASC.Web.Core/Files/FileUtility.cs b/web/ASC.Web.Core/Files/FileUtility.cs
index 0edcd11e9d..b46a985db6 100644
--- a/web/ASC.Web.Core/Files/FileUtility.cs
+++ b/web/ASC.Web.Core/Files/FileUtility.cs
@@ -254,52 +254,62 @@ namespace ASC.Web.Core.Files
 
         public bool CanImageView(string fileName)
         {
-            return ExtsImagePreviewed.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsImagePreviewed.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanMediaView(string fileName)
         {
-            return ExtsMediaPreviewed.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsMediaPreviewed.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanWebView(string fileName)
         {
-            return ExtsWebPreviewed.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsWebPreviewed.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanWebEdit(string fileName)
         {
-            return ExtsWebEdited.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsWebEdited.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanWebReview(string fileName)
         {
-            return ExtsWebReviewed.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsWebReviewed.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanWebCustomFilterEditing(string fileName)
         {
-            return ExtsWebCustomFilterEditing.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsWebCustomFilterEditing.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanWebRestrictedEditing(string fileName)
         {
-            return ExtsWebRestrictedEditing.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsWebRestrictedEditing.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanWebComment(string fileName)
         {
-            return ExtsWebCommented.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsWebCommented.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanCoAuhtoring(string fileName)
         {
-            return ExtsCoAuthoring.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsCoAuthoring.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         public bool CanIndex(string fileName)
         {
-            return ExtsIndexing.Contains(GetFileExtension(fileName), StringComparer.CurrentCultureIgnoreCase);
+            var ext = GetFileExtension(fileName);
+            return ExtsIndexing.Exists(r => r.Equals(ext, StringComparison.OrdinalIgnoreCase));
         }
 
         #endregion