unwanted characters in script

hi everyone, i tried to google my question, but did not find anything even similar to my problem. i have a few sql scripts for creating tables and altering tables and some for stored procedures. if i open them in heidi, there are characters added before some specialCharacters, and german characters ÄÖÜß are replaced thoroug others. in my comments, it did not disturb me. but now i have this problem in regexp. every time i open the script, there is one more character added. the first attached picture was in the beginning like [A-ZÄÖÜ]. i did not check it for a while. the second picture is after one time opening (other procedure). here are added the characters  and Â. does anyone have an explanation or an idea how to solve my problem?