HUH?
I just accidentally clicked one of those buttons - which are tiny and no text (only a tooltip)…
…and it replaced a bunch of items with… nothing. No undo that I could find, Ctrl+Z doesn’t work. Completely messed up a script. 
And where’s “Match whole word”?
This is not an improvement over EditPythonScript. The only thing that is good about this function in ScriptEditor is it tells you the line numbers where the matches are found.
Hey @Helvetosaur,
I can see that being surprising and somewhat frustrating, thanks for letting us know, I’ve added a YouTrack for this issue so that it can get fixed 
.
– cs
Hi @CallumSykes , I see that if I use the Search&Replace in ScriptEditor in Windows in the latest build this still hasn’t been fixed. This needs to be done asap! If you accidentaly type in a wrong replace string that is already used in the code then you are in trouble if you can’t undo this.
I also see that “Toggle matching case in search panel” is OFF by default… that is also a big mistake since the use of lower case versions of the command names are often used. So IMO this needs to be ON by default.
There are still lots of small bugs in the ScriptEditor that makes it less efficient to use than the PythonScriptEditor so please, please prioritize to fix this.
I just lost quite a bit of editing of a code I am working on because I could not undo a search&replace. Loosing work on 3D modelling is one thing, since it is so visual, but loosing work on scripting is a different ball game since this is just text, and text is not very visual, so it can be demanding to both see and remember what was changed and thus lost since the last save.
In V8 or V9?
Are there any you can name in particular so I can get them ticketed? I use the script editor a lot myself and try to log anything I find whilst using it.
I’m sorry to hear this I’ve experienced it myself and it’s super frustrating. I’ll test today, log anything I find and link here. If I can’t repro I’ll ask you more questions about it.
I think remembering your settings would solve this.
Put a fix related to this in 8.24 SRC
RH-89117 Undo Redo does not work after Replace
RH-89117 is fixed in Rhino 8 Service Release 24