As shown below, not closing alias brackets can cause SSMS column display readability issues and more importantly your query to not execute as expected.
--declare table
DECLARE @t TABLE (c1 varchar(10),c2 varchar(10));
--insert some data
INSERT INTO @t(c1,c2) VALUES ('one','two');
INSERT INTO @t(c1,c2) VALUES ('three','four');
--view data
SELECT
c1 AS [column1
,c2 AS [column2]
FROM @t;
If you send the results to text, you can observe what is occurring and c2 is not considered in the query.
The above was using the latest SSMS v17.0 version.