I just upgraded from LR3.6 to 4.0. When trying to import images the import module freezes for a few minutes and then displays the import screen. However, when selecting a source the program freezes again and eventually crashes.
I had the same issue when upgrading to 3.6 some time ago and then found that disabling some USB controllers solved the problem. This works for LR4 as well.
As I don't need all USB connections this is a workable solution, however, disabling controllers should not be necessary to run a program.
System is an Acer Aspire 7811 64 bits w/ Intel i7, Win 7 Home Premium, 8 GB internal mem and no external drives.
If anybody experienced this problem and has a good solution I would be very grateful to hear from you.
I received an answer from Adobe tech support on the USB issue. They listed it as a bug and will take action if there are more reports of this behavior.
Meanwhile the solustion as mentioned in the first post still works for me, LR4 is now importing images fast and without problems.
Unfortunately I found no good way as not all of the controllers have a description. However, on my system, the mouse and keyboard controller is called Microsoft Mouse and Keyboard Detection Driver.
I didn't reboot windows but restarted LR after I disabled each driver.
I'm having the same problem. My system is a Lenovo Thinkpad X220 Tablet running Windows 7 x64. I tried removing my Expresscard USB 3 controller but that didn't do it. Control Panel shows 2 USB controllers on the motherboard, or more correctly, 2 instances of Intel 6 Series/C200 Series Chipset Family USB Enhanced Host Controller. Uninstalling either instance seems to solve the problem. Uninstalling the 2nd instance took out my mouse, keyboard, phone Blu-Ray drive, etc. I reinstalled that and uninstalled the 1st instance which also solved the problem without the side effects. It's likely something isn't working and I haven't found it yet.
It would definitely be nice if Adobe would provide a software fix of this.
One specific item that I now know causes these kinds of problems is an Adroid Phone plugged in.
The android phone can look like an external drive and LR tries to find photos on it.
There are a number of problems that occur then
The results are
It gets even worse on some of the newer phones that don't show up as a drive letter so you use "webDav" to force a drive-letter.
The webDav drive access is slow and often locks up for a time (explorer, not LR even), so when LR sees the drive letter it has even more problems.
My soloution? don't use LR with my phone plugged into a USB port!