Hi,
Pressing 'replace in all project files' rather than 'in selection' causes some problems; and this is quite easily done accidentally with a slip of the mouse since the buttons are quite close together and next to each other.
Problem 1: After the accident, the only way to get back to where you were is to press undo once for each replacement made. Mine said 'Found and replaced 82 items.' This took some time to get back, which then led to...
Problem 2: After pressing undo several times, the IDE crashed.
After a bodged search and replace, UNDO should undo ALL the changes made by the Search and Replace box, with one click.
James