Excel VBA: I get a compile error when using worksheet codename references in my workbook, but not when using sheets ("tab name"). Happens only if I have vba code associated with the worksheet in which I am referencing. Happens only to SOME users but not all. I had to switch over to using codename references, and as soon as I replaced all "sheets ("Main").xxx" with "sheet3.xxx" direct reference, SOME users are now getting "compile error: Object library invalid or contains references to object definitions that could not be found" and what the user sees is VBA IDE interface highlighting the first line of code which is associated with the worksheet that I am now using "sheet3.xxx" references on. It's not specific line of code, but I find it's the fact that ANY code is associated with sheets that I am now referencing using direct codenames, and only SOME users.