Shiny apps is not working

I've started a course using shiny and no examples are working, even very basic ones. All of them return the same error. They seem to be working for other people. Is there some setting I need to adjust?
Here is an example from the console

# Load shiny
> library(shiny)
> 
> # Create a UI
> ui <- fluidPage("Hello World!")
> 
> # Create a server
> server <- function(input, output) {}
> 
> # Create a shiny app
> shinyApp(
+   ui = ui,
+   server = server)

Listening on http://127.0.0.1:3508
Error in staticPath(path) : `path` must be a non-empty string.

Any example I try with shiny returns this error and I cannot figure out how to fix it!

Is this a script? Why all the > symbols? This runs for me. You have to save it as a script.

# Load shiny
library(shiny)

# Create a UI
ui <- fluidPage("Hello World!")

# Create a server
server <- function(input, output) {}

# Create a shiny app
shinyApp(
		ui = ui,
		server = server)

It's a script, I just copied from the console to grab everything in one go. Saving as a script does not fix the error