check for update gives error

When I use the check for upgrade from the tools menu, I get the following errors

System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.Xml.XmlException: An error occurred while parsing EntityName. Line 12, position 34.
at System.Xml.XmlTextReaderImpl.Throw(Exception e)
at System.Xml.XmlTextReaderImpl.HandleEntityReference(Boolean isInAttributeValue, EntityExpandType expandType, Int32& charRefEndPos)
at System.Xml.XmlTextReaderImpl.ParseText(Int32& startPos, Int32& endPos, Int32& outOrChars)
at System.Xml.XmlTextReaderImpl.FinishPartialValue()
at System.Xml.XmlTextReaderImpl.get_Value()
at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r)
at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r, LoadOptions o)
at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
at System.Xml.Linq.XDocument.Load(TextReader textReader, LoadOptions options)
at Xamarin.VisualStudio.UpdateClient.<>c__DisplayClass4_0.b__0() in C:\data\lanes\3513\00fa5cc4\source\xamarinvs\src\Core\VisualStudio\Updater\UpdateClient.cs:line 82
at System.Threading.Tasks.Task

1.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---
   --- End of inner exception stack trace ---
   at Xamarin.VisualStudio.Shell.UpdateService.<>c__DisplayClass34_0.<CheckForUpdates>b__0(Task[] tasks) in C:\data\lanes\3513\00fa5cc4\source\xamarinvs\src\Core\VisualStudio.Shell\Updater\UpdateService.cs:line 239
   at System.Threading.Tasks.TaskFactory

1.<>c.b__57_0(Task

1 completedTasks, Object state)
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask

2.InnerInvoke()
at System.Threading.Tasks.Task.Execute()
--- End of inner exception stack trace ---
---> (Inner Exception #0) System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.Xml.XmlException: An error occurred while parsing EntityName. Line 12, position 34.
at System.Xml.XmlTextReaderImpl.Throw(Exception e)
at System.Xml.XmlTextReaderImpl.HandleEntityReference(Boolean isInAttributeValue, EntityExpandType expandType, Int32& charRefEndPos)
at System.Xml.XmlTextReaderImpl.ParseText(Int32& startPos, Int32& endPos, Int32& outOrChars)
at System.Xml.XmlTextReaderImpl.FinishPartialValue()
at System.Xml.XmlTextReaderImpl.get_Value()
at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r)
at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r, LoadOptions o)
at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
at System.Xml.Linq.XDocument.Load(TextReader textReader, LoadOptions options)
at Xamarin.VisualStudio.UpdateClient.<>c__DisplayClass4_0.b__0() in C:\data\lanes\3513\00fa5cc4\source\xamarinvs\src\Core\VisualStudio\Updater\UpdateClient.cs:line 82
at System.Threading.Tasks.Task

1.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---
   --- End of inner exception stack trace ---
   at Xamarin.VisualStudio.Shell.UpdateService.<>c__DisplayClass34_0.<CheckForUpdates>b__0(Task[] tasks) in C:\data\lanes\3513\00fa5cc4\source\xamarinvs\src\Core\VisualStudio.Shell\Updater\UpdateService.cs:line 239
   at System.Threading.Tasks.TaskFactory

1.<>c.b__57_0(Task

1 completedTasks, Object state)
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask

2.InnerInvoke()
at System.Threading.Tasks.Task.Execute()
---> (Inner Exception #0) System.AggregateException: One or more errors occurred. ---> System.Xml.XmlException: An error occurred while parsing EntityName. Line 12, position 34.
at System.Xml.XmlTextReaderImpl.Throw(Exception e)
at System.Xml.XmlTextReaderImpl.HandleEntityReference(Boolean isInAttributeValue, EntityExpandType expandType, Int32& charRefEndPos)
at System.Xml.XmlTextReaderImpl.ParseText(Int32& startPos, Int32& endPos, Int32& outOrChars)
at System.Xml.XmlTextReaderImpl.FinishPartialValue()
at System.Xml.XmlTextReaderImpl.get_Value()
at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r)
at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r, LoadOptions o)
at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
at System.Xml.Linq.XDocument.Load(TextReader textReader, LoadOptions options)
at Xamarin.VisualStudio.UpdateClient.<>c__DisplayClass4_0.b__0() in C:\data\lanes\3513\00fa5cc4\source\xamarinvs\src\Core\VisualStudio\Updater\UpdateClient.cs:line 82
at System.Threading.Tasks.Task

1.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---
---> (Inner Exception #0) System.Xml.XmlException: An error occurred while parsing EntityName. Line 12, position 34.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.HandleEntityReference(Boolean isInAttributeValue, EntityExpandType expandType, Int32& charRefEndPos)
   at System.Xml.XmlTextReaderImpl.ParseText(Int32& startPos, Int32& endPos, Int32& outOrChars)
   at System.Xml.XmlTextReaderImpl.FinishPartialValue()
   at System.Xml.XmlTextReaderImpl.get_Value()
   at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r)
   at System.Xml.Linq.XContainer.ReadContentFrom(XmlReader r, LoadOptions o)
   at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XDocument.Load(TextReader textReader, LoadOptions options)
   at Xamarin.VisualStudio.UpdateClient.<>c__DisplayClass4_0.<CheckForUpdates>b__0() in C:\data\lanes\3513\00fa5cc4\source\xamarinvs\src\Core\VisualStudio\Updater\UpdateClient.cs:line 82
   at System.Threading.Tasks.Task

1.InnerInvoke()
at System.Threading.Tasks.Task.Execute()<---
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