SOLVED
Wow! I found the error!
The error, which appeared to be similar to https://gitlab.gnome.org/GNOME/gimp/issues/2672 was caused by a dead driver.
When I opened "Devices and printers" there was an "Unknown Device" and when I clicked on it the whole window froze (the same that happens in GIMP).
After about 30 sec it un-froze and disappeared. I got a message which stated that there were some devices that needed repair, so I opened device manager and at the very bottom of the page there is an option which is Universal Serial bus Controllers or USB-controllers. Under that option I found a dead drive of an unknown device. I uninstalled that and everything works flawlessy now! I think GIMP might have tried to search that device for files or similar but couldn't reach it (same as Devices and Printers couldn't).
Long story short: Uninstall dead drivers of USB or other storage units to hinder GIMP from searching forever.
Wow! I found the error!
The error, which appeared to be similar to https://gitlab.gnome.org/GNOME/gimp/issues/2672 was caused by a dead driver.
When I opened "Devices and printers" there was an "Unknown Device" and when I clicked on it the whole window froze (the same that happens in GIMP).
After about 30 sec it un-froze and disappeared. I got a message which stated that there were some devices that needed repair, so I opened device manager and at the very bottom of the page there is an option which is Universal Serial bus Controllers or USB-controllers. Under that option I found a dead drive of an unknown device. I uninstalled that and everything works flawlessy now! I think GIMP might have tried to search that device for files or similar but couldn't reach it (same as Devices and Printers couldn't).
Long story short: Uninstall dead drivers of USB or other storage units to hinder GIMP from searching forever.