Query execution failed for dataset... Incorrect syntax near '}' - reporting-services

Question

The following error occurs when I run a report in SSRS Report Portal:
An error has occurred during report processing. (rsProcessingAborted)
Query execution failed for dataset 'DataSet1'. (rsErrorExecutingCommand)
Incorrect syntax near '}'.
<DataSet Name="EstimateYear">
<Query>
<DataSourceName>DataSource1</DataSourceName>
<CommandText>
SELECT
{
} ON 0,
{
(
[EstimateYear].[Year].[Year],
ORDER
(
[EstimateYear].[Version].[Version],
[EstimateYear].[Version].MEMBER_VALUE,
ASC
)
)
} ON 1
FROM
[Model]
WHERE
{
[EstimateYear].[CurrentVersion].[1]
}
</CommandText>
<rd:DesignerState>
<QueryDefinition xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://schemas.microsoft.com/AnalysisServices/QueryDefinition">
...
</QueryDefinition>
</rd:DesignerState>
</Query>
<Fields>
<Field Name="Field1">
<DataField>...</DataField>
<rd:TypeName>System.String</rd:TypeName>
</Field>
<Field Name="Field2">
<DataField>...</DataField>
<rd:TypeName>System.String</rd:TypeName>
</Field>
<Field Name="Field3">
<Value>=...</Value>
</Field>
</Fields>
</DataSet>
Please note: I have a custom security extension applied to the Report Server. I am running tests at the time of writing to rule out whether the is causing the error.
Can you see an error with this or have any idea where else the error might be happening?