SQL continues excecution when syntax error

I recommend that you change the script as below:

UPDATE Table1 SET status = 'DoSomething'

FROM Table1 INNER JOIN Table2 ON Table1.TabId = Table2.TabId

WHERE Table1.status = 'Ready'

AND Table2.xData IS NOT NULL;

This script can not only prevent the incident you have gotten but also validate the relationship between table1 and table2 before updating even though I know tabid only exists in table1....