Sometime, simple and basic problem can trap experts. This happened last week with one of my senior, who was trying to generate some scripts and saving output scripts to an output text file. On execution of these scripts he found that for some queries text was not complete. He tried to get result in text format but problem was same.
If you are facing same basic problem of SQL Server Management Studio then no need to worry, as you just need to make some changes in SSMS options.
Go to TOOLS -- > OPTIONS -- > QUERY RESULTS -- > Result to Text -- > Maximum number of characters displayed in each column
Default value is 256, which is too less, update it to your desired length. You can extend it to 8192 characters maximum.