Whenever I try to open nautilus it takes about 30 seconds for it to come up, regardless if it is from a launcher or the terminal. However, when I open it from the terminal this pops up right before it starts:
Error creating proxy: Error calling StartServiceByName for org.gtk.vfs.MTPVolumeMonitor: Timeout was reached (g-io-error-quark, 24)
Nautilus-Share-Message: 11:23:39.053: Called "net usershare info" but it failed: Failed to execute child process “net” (No such file or directory)
This also affects any program that has an open file/folder dialog, and it also causes similar problems in other file explorers like dolphin and thunar. I've also tried CLI based file explorers like ranger, which just refuses to open, and midnight commander, which surprisingly works with no problems.
Originally I installed the 18.04 beta and this problem was not present. However, shortly after the release, this problem started and I've been dealing with it ever since.