Thank you for your report! Is this a reproducible bug or a one-time event? Could you provide more details about your system and concrete instructions on how we can reproduce this bug? ( feedback@tonelib.net )
iMac (Retina 5K, 27-inch 2017) Processor 3.4 Ghz Intel Core i5 Memory 40 GB 2400 MHz DDR4 Specific instructions: Create a new preset, once completed...try to rename the preset in the left hand column. Double click on the current name->enter new name, and when I hit <return> ToneLib-GFX closes down. Now curiously, if I enter the new name in the top panel, and hit <return> ToneLib-GFX does not close.
Now it should be fixed, please download the latest build and let us know if you experience any other issues. Thanks again for you report!