MSB4018: The "CompileModel" task failed unexpectedly.

MSB4018: The "CompileModel" task failed unexpectedly.

System.Xml.XmlException: Data at the root level is invalid. Line 1, position 1.

  at System.Xml.XmlTextReaderImpl.Throw(Exception e)

  at System.Xml.XmlTextReaderImpl.Throw(String res, String arg)

The above error raised in few SSRS reports which has the DyanmicsOLAP data source.

Solution:

Open the report in Visual studio and verify that the Datasource property is proper on the data set of the tables attached to report

In My case, the issue raised because the DynamicsOLAP data source is not available or not able to connect

Also, Verify that the on Microsoft Dynamics AX under System administrator menu, Analysis report server, the default server and data source is selected or configured properly.