Error: No Excel Calculation Services is available in the farm.

Error:

Sometime you will get error like below, while you are loading excel sheet in your SharePoint Excel Web Access web part.

1. No Excel Calculation Services is available in the farm.

(or)

2. There was an error in communicating with Excel Calculation Services http://SenMoss:56737/SharedServices2/ExcelCalculationServer/ExcelService.asmx exception: The request failed with HTTP status 503: Service Unavailable.

(or)

3. Unable to reach Excel Calculation Services http://SenMoss:56737/SharedServices2/ExcelCalculationServer/ExcelService.asmx.

Reason:

Your IIS application pool for Excel Calculation services may not be enabled. 

Solution:

1. Go to IIS (Type "InetMgr" in Command Prompt")

2. Open "ApplicationPools" node 

3. Select "OfficeServerApplicationPool".

4. Right Click on ir and select "Start"