Brief summary of issue / Description of requested feature:

Mudlet crashes frequently when viewing medium to large scripts

Steps to reproduce the issue / Reasons for adding feature:

1. Create a fresh profile.
2. Create a script/alias long or wide enough for the scroll bar to appear.
3. Scroll with the bar or navigate with arrow keys. Try moving the visible area.
4. Mudlet promptly freezes and crashes.

Error output / Expected result of feature

4. Mudlet should modify the visible area and follow your cursor or scroll bar movements.

Some examples of crashes witnessed

1. Steps mentioned above: Cursor movement out of the visible area
   

2. Typing until you leave the visible area
   

3. Drag the scroll bar to move the visible area
   

4. Trigger already crashing when clicking into script area
   

Extra information, such as Mudlet version, operating system and ideas for how to solve / implement:

Thanks to discord users Kuririn, the Monk Healer and Ondine for reporting the bug and showing a set of steps to reproduce the crash
Reproduced on Win10, Mudlet version 4.0.1.