When it comes to instability in SOLIDWORKS, do consider to reinstall the .Net Framework. The .Net Framework is one of the prerequisites to SOLIDWORKS and all its core products. If a .Net Framework installation failed or missing or out of date, it could cause crashing or difficulty to start SOLIDWORKS.
.Net Framework versions consist of: 3.5 and 4.7. For SOLIDWORKS core products, .Net Framework 4.7 is the only prerequisite that need to be installed. The .Net Framework 3.5 is for installing the optional prerequisite VSTA (Visual Studio Tools for Applications 2005). VSTA is a prerequisite is needed if you plan on creating, editing or running .Net macros for SOLIDWORKS.
.Net Frameworks will need Admin access in order to reinstall it. First, for Windows 10 is to right-click your start menu and go to ‘Apps and Features’ at the top.
Click on ‘Programs and Features’On the Apps and Features Page, on the right-hand side. (If your window is too small, the Programs and Features link will be listed at the bottom of your list of programs)
Click on the link “Turn Windows features on or off” located on the left-hand side in Programs and Features.
In the Windows Features dialog, untick both .Net Framework 3.5 and 4.7 then say ‘OK’. This will uninstall them and prompt you to reboot your computer.
Reboot your computer and go back to the same location and recheck both .Nets and click ‘OK’ to reinstall them. if let say there are updates needed it will prompt you to download those updates from the Microsoft Update Server. After the process ended you have successfully reinstalled the .Net Frameworks and can retest SOLIDWORKS to see if you solved any instability you might be facing.
For Windows 7 Machines, the process is almost the same. You can access programs and features from your control panel and the .Net Framework 4.7 will be listed in your programs and features instead of the Windows Features dialog. In this case, you can simply repair your .Net Framework 4.7 instead of reinstalling it (you will be given the option to repair if you right click and say uninstall/change).
Please get your IT to help resolve these issues as they are often related to your Operating System installation or your connection to the Microsoft Update servers.