PowerPivot Error "Failed to connect to the server. Reason: Unspecified error" when importing other files

Question

I have been getting the error below on a regular basis when attempting to import Excel, Text, or Access files.
I'm running Office 2010 (SP1), and PowerPivot (SP1). After reading a similar thread I reinstalled PowerPivot. It worked until I closed Excel. Now it recuses to allow import or update of these files. I really need it to work. Anyone have an solution or even
something to try - other than uninstalling and reinstalling PowerPiviot everytime I need to import or refresh files?
Thanks,
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Error Message:
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Unspecified error
Failed to connect to the server. Reason: Unspecified error
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Call Stack:
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   at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection)
   at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionInternal.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   at System.Data.OleDb.OleDbConnection.Open()
   at Microsoft.AnalysisServices.BackEnd.RelationalDataSourceConnection.InitializeConnectionObject(String connectionIdentifier)
   at Microsoft.AnalysisServices.BackEnd.RelationalDataSourceConnection.InitializeConnectionObject(String connectionIdentifier)
   at Microsoft.AnalysisServices.BackEnd.RelationalDataSourceConnection.Open(String& connectionIdentifier)
   at Microsoft.AnalysisServices.BackEnd.RelationalDataSourceConnection.Open()
   at Microsoft.AnalysisServices.Common.DataSourceBasic.TestConnection()
   at Microsoft.AnalysisServices.Common.DataSourceBasic.ClickTestConnection(Object progressControl)
============================

Answer 1

Hi San,
What's the version of your PowerPivot? Please refer to the article to check the version of PowerPivot for Excel:
http://powerpivot-info.com/post/89-q-how-can-i-check-what-version-of-powerpivot-for-excel-is-installed-on-my-machine
We can download the latest PowerPivot for Excel version from:
http://www.microsoft.com/en-us/download/details.aspx?id=29074
In addition, please help to collect windows events log information to us for further investigation. If you cann't import Excel, TEXT or Access data into PowerPivot data model, you can try to directly copy your data into it.
Regards,
Elvis Long
TechNet Community Support