Hi @AxisAngle thank you for the report. Some questions for you!
Which place is this?
What is the use-case for players copying large amounts of text into experience on mobile? It looks like a player configuration / settings JSON …?
Do you know which properties are enabled for this specific textbox or have a simple place file w/ a text box that repros the issue? Just in case if the issue is tied to a specific combination of settings (multiline etc): TextBox | Documentation - Roblox Creator Hub
Players can configure a control scheme, then copy and send it to their friends or to me where I can modify and then implement it as a default control layout in code.
I can copy my own configuration and implement it as a default control layout in code.
It is Lua format, I wrote a mostly functional Lua interpreter in Luau, so players can run arbitrary control layout configuration code.
I binary searched to the crash point and found that any TextBox, if you try to load more than 5000 characters, will crash Robox on Android (at least my S24 and some other models, but it could be all of them).
Here’s an example place with 5001 characters in a TextBox with default Properties except for ClearTextOnFocus = false. Click on the TextBox and it may crash the Roblox App.
It appears that if I try to manually enter more than 5000 characters on my S24, it will not let me. So I think this has something to do with an arbitrary limitation of Android, or at least some devices.