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Your LimeSurvey version: CE 6.5.2+240402 
Own server or LimeSurvey hosting:Own server
Survey theme/template: fruity
MSSQL db
IIS
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(Write here your question/remark)
After upgrading from 6.0 to 6.4 we discovered existing surveys and copies of them cannot be activated. These are surveys that had been activated several times in 6.0 and previous versions. After updating, trying to activate once results in this error:

500: Internal Server Error CDbCommand failed to execute the SQL statement: SQLSTATE[42000]: [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]An object or column name is missing or empty. For SELECT INTO statements, verify each column has a name. For other statements, look for empty alias names. Aliases defined as "" or are not allowed. Change the alias to a valid name.

Trying to activate again results in this message:

The survey response table could not be created.
Usually this is caused by having too many (sub-)questions in your survey. Please try removing questions from your survey.

NEW surveys created from scratch can be activated once and only once. Deactivating and then activating them again results in the same error messages show above. This pattern happens even when creating a basic survey and not adding anything other than the default first question.

I upgraded again from 6.4 to the current 6.5 build and the problem persists.


Any suggestions would be greatly appreciated.
 

I don't see a quick fix. That looks like an issue in combination with the MS SQL Server. LimeSurvey is lacking a proper testing with SQL Server. The installed base is low, so you will run into new bugs more often.
Best thing to do is to update to the lastest LimeSurvey version and try again. If that won't help submit a bugreport.

Hello, i faced same problem after update
Solution form me appeared to be changing in limesurvey\application\helpers\admin\activate_helper.php following line     
to