Zuu opened the ticket and wrote:

To trigger this bug:
* Select a translation with long enough strings (English UK do not trigger the bug, but for example Swedish does)
* Make sure to enable the ai developer tools.
* Open the AI Debug window
* Resize it to the smallest width

When the edit box become too small => Kaboom - assert is triggered.

Possible solutions:
* Change edit box drawing code to not trigger assert when the edit box becomes too small
* Set a minimum width of the edit box in the AI Debug window to say 10 pixels. (you sometimes want to make the window as small as possible to reduce the performance hit of keeping it open, without closing it). If this solution is chosen, then perhaps all other edit boxes should be checked so that they cannot trigger the assert.

Reported version: trunk
Operating system: All

This issue was imported from FlySpray: https://bugs.openttd.org/task/4010