This issue occurs when editing the alias via the grid in the diagram tab, then going back to query tab to visualize the query, and then clicking back into the diagram tab.
When working in Query Builder and going between diagram and query tabs to modify and edit the query, it generates incorrect syntax.
If a column is noted with an alias, AS 'TEST 1', the aliases will have extra quotations added, AS '''TEST1'''.
WORKAROUND:
Do not edit or make changes to the alias via the grid. Or manually fix any syntax/quotation changes.
STATUS:
Waiting for a fix in a future release of Toad Data Point.