Fixing DrtBase.cs and updating global.json version

global.json

@@ -1,6 +1,6 @@
 {
   "tools": {
-    "dotnet": "3.0.100-preview-009756",
+    "dotnet": "3.0.100-preview-009764",
     "vswhere": "2.5.2"
   },
   "msbuild-sdks": {

src/Microsoft.DotNet.Wpf/test/Common/TestServices/DrtBase.cs

@@ -2712,7 +2712,13 @@ public override void Write(char value)
                         _logFile.Flush();
                     }
 
-                    _output.WriteLine($"{value}");
+                    try
+                    {
+                        _output.WriteLine($"{value}");
+                    }
+                    catch
+                    {
+                    }
                 }
             }
 
@@ -2733,7 +2739,11 @@ public override void Write(char[] buffer, int index, int count)
 
                     var sb = new StringBuilder();
                     sb.Append(buffer, index, count);
-                    _output.WriteLine(sb.ToString());
+                    try
+                    {
+                        _output.WriteLine(sb.ToString());
+                    }
+                    catch { }
                 }
             }
 
@@ -2764,7 +2774,11 @@ public override void Write(string value)
                         _logFile.Flush();
                     }
 
-                    _output.WriteLine(value);
+                    try
+                    {
+                        _output.WriteLine(value);
+                    }
+                    catch { }
                 }
             }