Network/internet doesn't work
RaspiEmu does its best to select the appropriate QEMU binary for your system; however sometimes it may not be choose the best one.
To mediate this, you can select a different version of QEMU from the Preferences window > Emulator tab.
The Pi 2 does not have TCP/UDP networking. The closest you can get is text-over-CLI, which is good for pasting text into files. Maybe this can be used to paste binary data, I am not to know.
Crashes on launch
Please make sure that your copy is up-to-date. The latest versions are available at http://snorfi.us/downloads, with pre-release versions available here. or via gumroad at http://gum.co/raspiemu.
Make sure your system is compatible. The current stable OS is between OS X 10.8 and 10.12, with support for High Sierra a little unstable.
If your app is in a restart loop (will launch, then relaunch), please update to version 2.7.6, or delete the file ~/Library/Preferences/us.snorfi.RaspiEmu.plist
No GUI, but CLI works
As of v2.8, this shouldn't be an issue. If you downloaded the image using a previous version, follow the steps below to re-download the disk image.
1. Open a Terminal window and type 'raspiemu diskconfig'
3. In the newly opened pop-up window, type 'd', followed by 'pi1' or 'pi2'. This will delete the existing image, making space for the new one.
4. Once step 3 is complete, re-launch using step 1, and type 'i', (instead of 'd')
5. Enter either '2' or '4', which will download and install a full Raspbian image, approximately 1.7GB.
Pi 1/2 doesn't start
Try repairing the runtime. This can be done via Config > Configure runtime, by typing 'repair' when prompted. If you are prompted to install, then the runtime isn't set up - it's a good idea to follow through (by typing 'no' or 'yes')
Make sure you have entered valid arguments for QEMU. Try removing them by clicking the reset button in the Config > Emulation Arguments menubar item.
Make sure that your attached USB device is correct. Otherwise, try disabling it completely by clicking on "Change" in the Config > USB menubar item
If you are receiving 'not found' errors while in CLI, try re-downloading the disk image, as it is the boot disk. There's no way it'll work without it. This can be done via the Config > Configure Disk
As of version 2.7.14, Pi 2 GUI is disabled due to performance reasons. It can still be accessed via "combine"; the Start > Launch Pi 2 > GUI+CLI menu item.
Alternatively, it can be reenabled by enabling debug mode in the Preferences > General window.
Mouse doesn't work in Pi 2This is a known issue, and will be fixed as soon as possible.
Workaround: Use CLI, "Combine" (accessible via Start > Pi 2 menu items), or the Pi 1 GUI instead.
Update: Apperently this occurred in version 2.7.9. You could try downgrading to version 2.7.8, available here
If nothing of the above works, you could try a configuration reset by going to Preferences > Reset configuration.