I have had this same problem for a very long time.  I typically noticed it with the word "data".   If I were trying to type out a set statement and I said something like   proc sort data= it would actually show up in the editor like this as soon as I hit the equals sign proc sort datadata=   However, thanks to @Quentin's post, I have at least identified that the issue is tied to using libname statements like    libname data '/path/to/lib';   Unfortunately, this is a pretty common library name for me.  I'm going to stop using it until this bug is fixed, but it will still be there in other people's code that I have to work with.  Has been happening since at least EG 5 ... View more