Freezing FEFLOW 7.0 x64

FEFLOW 7.0 x64 freezes when trying to open a file, but it does open in x86. I need that specific version (7.0) in 64 bits for compatibility with a plug-in. Any ideas how can I fix that? I'm using Windows 11. Thanks in advance.  

Hola Cecilia, In general FEFLOW 7.0 is a very old version. Please be aware that Fully supported operating systems are Windows 7 Professional Service Pack 1 (64 bit), Windows 10 Pro (64 bit), Windows Server 2012 R2 Standard (64 bit) and Windows Server 2016 Standard (64 bit). The freezing behaivoir can be trigged by several issues, including the plug-in itself. I can only recommend you to work with the latest update of FEFLOW 7.0. Best regards Carlos Rivera