crash when pressing square root after Syntax error

[GuitarBilly]

hello, and thanks for this beautiful calculator.

Describe the bug
When i tried to use it as my real calculator the app crashed.
If you use the square root wrongly it first mentions Syntaxfout (Syntax error). When pressing square root once after that the app always crashes hard.

To Reproduce

1. press any number (optional)
2. press square root
3. press =
4. notice Syntaxfout (Syntaxerror) shows up in the screen. >>> first screenshot
5. press square root
6. the app crashes hard. >>> second screenshot

Expected behavior
The app can show an error message or inform the user, but it should not crash hard on an incorrect sequence of input.

Screenshots/videos

Smartphone (please complete the following information):

• Model = Nokia 6 - TA-1033
• OS = Android 7.1.2
• App version = 3.0.0
• Language = Dutch

Additional context
none.

[ikanakova]

On Samsung Galaxy A53, Android 14, version 3.0.0 from F-Droid, czech localization works as it should - it writes a syntax error, but does not crash.

[Darkempire78]

On Samsung Galaxy A53, Android 14, version 3.0.0 from F-Droid, czech localization works as it should - it writes a syntax error, but does not crash.

Same for me on my Pixel 6