Shiny App takes long time to load then immediatly disconnects from server

My Shiny App runs perfectly well on my local server, but when I try to run it on shinyapps.io, it takes quite a while to load, and when it finally does, it immediately disconnects. I'm assuming this is happening because it has to load too much data (it loads two DFs, both of which contain several million observations), but I'm not sure. For context, I only have the free account on shinyapps.io, so that may be limiting performance. Should I find more efficient ways to load the data (e.g., with something like the arrow package? I don't have any experience with this.), or is there potentially something else going on? Thanks!

You can confirm whether the source of the error/disconnection is not enough memory or something else by checking the logs of your app on shinyapps.io. Please post your logs leading up to the disconnect here so we have more details.

If you are using shinyapps.io, logs are under the “Logs” tab found in an app’s settings, or at the URL https://www.shinyapps.io/admin/#/application/ID/logs, where ID is the app’s ID number (not its name).