LearnR generates "Reactive context was created in one process and accessed from another' when calling DT::datatable()

Question

The following learnR tutorial generates an error when it is "run", and the code box's run button is pressed. The notebook works fine if I omit the DT:datable function but I need to use this in my true implementation in order to get access to the escape parameter.

---
output: 
  learnr::tutorial
runtime: shiny_prerendered
---

``{r setup, include=FALSE}
library(shiny)
library(learnr)
``
``{r tst1, exercise = TRUE, exercise.eval = TRUE}
data(iris, package = "datasets")
DT::datatable(iris)
``

For formatting reasons I have only shown two backticks for the code blocks above instead of the normal three.

Answer 1

After checking my versions of packages using sessionInfo() is decided to reinstall learnr and rlang as these were both github versions rather than CRAN versions. Amazingly, this fixed the problem. I cannot say which of the two was at fault.