Sql Server stored procedures full of errors

I am trying to use DataGrip with SQL Server database. I can see that a perfectly normal stored procedure is showing full of "errors":

ALTER PROCEDURE [dbo].[System_setSomething] (@SIMICC as varchar(20), @SecS2K as Int, @Lat AS VARCHAR(20), @Lon AS VARCHAR(20))
AS

After each AS in parameters it says: ": expected, got varchar"

In the second line, after the AS it says: ": expected, got BEGIN"

At the first parameter it says: "), <identifier>, AS, EXTERNAL, FOR or WITH expected, got '@SIMICC'

For all these mean? As per SQL Server syntax this procedure is perfectly correct.