The standard Windows uninstaller may leave behind registry entries and residual files, causing conflicts. F-Secure provides a dedicated removal tool for a complete clean.
GPU drivers that lack optimization for your simulator version can cause the UI process to hang. fsmainui.exe
Right-click your graphics card (NVIDIA, AMD, or Intel) and select . The standard Windows uninstaller may leave behind registry
If fsmainui.exe is causing high CPU usage, it is usually because it is actively displaying a large scan result, updating, or experiencing a conflict with another program. Right-click your graphics card (NVIDIA, AMD, or Intel)
[System.InvalidOperationException] - fsmainui.exe has encountered an error and needs to close. 1. High CPU or Memory Usage
While not common, fsmainui.exe may temporarily use high system resources during a full system scan or definition updates . If it constantly consumes over 20-30% CPU, it suggests a corrupted installation or conflict with another program.