我们在这里为初学者提供了重要的提示和建议，以便用户更加容易快速的掌握使用我们的基本软件 RFEM 和 RSTAB。
1. the installed material library "Materials.dbd" with the current Materials, and
2. the user-defined material library "Materials_User.dbd.".
One of the libraries has probably been transferred from another version or computer. In order to solve the problem, you shoul copy the second library as well.
Otherwise a new installation is necessary. In that case, the program including the broken library is uninstalled automatically.