Note that RStudio is only part of the issue; RStudio runs as an IDE --- Integrated Development Environment --- over whatever version of R you have installed.
For us to help, you need to be clear on:
- What versions of R are you and your colleague running?
- Have you installed all of the R packages your colleagues' code required?
Although it is difficult to be sure, your note suggests that the root of your problem could be as simple as not having the correct versions of the necessary packages installed...
Please check the above and report back...