See the FAQ https://www.axcrypt.net/support/faq/#lavasoft-crash . If you’re getting “File Encryption for .NET and Mono has stopped working. A problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available.” you have the Lavasoft Web Companion installed, whether you know it or not, I’m 99% sure. So far, we’ve had many users reprots this error and exactly 100% have finally found the Lavasoft component, even after initial statements of not having it, and after uninstall all works fine again.