Finder Crash in High Sierra

Hi. Over the last days is occured to me several times, that when I tried to rename a PDF in List view, which is stored on a Network drive, After renaming it, it kept its old name and the Finder froze completely. After Force-quitting, the Finder stays quit and desktop icons or Finder windows do not reappear. The dock stays available to open other apps but I may not open files from inside those apps. My Safari froze as well now, because I was trying if Save as was possible as well. So now I retyped this Wohle text on my phone and Need to force-reboot the iMac. Horray. Any thoughts?