suddenly no longer able to deploy shiny app

I am suddenly no longer able to deploy my shiny app. I get the following error message:

"Error: Unhandled Exception: Child Task 864722097 failed: Error building image: Error building readr (1.4.0). Build exited with non-zero status: 1
Execution halted"

Also sliderInput UI (numbers are black now, before they were white) suddenly changed when running locally.

This happened after upgrading some packages.

May I ask for some help in this matter. Kind regards

...

Problem solved, deployment working again.

I made a dplyr upgrade and I think this solved the problem.

Kind regards