I cannot count the hours I have spent fixing BlackBerry devices with 507 errors. This error is explained in great detail in our article detailing the BlackBerry Java Virtual Machine error codes. 
Error 507 Unsatisfied Link A dependency on a .COD file could not be satisfied because the .COD file is missing.
Isn’t that enlightening? Essentially I have found it to mean that you have no operating system installed on your BlackBerry. This is usually caused by an error in the upgrade process while upgrading your OS. I have had it happen twice recently, once when trying to upgrade on my Macbook using VMware fusion and another time when upgrading an OS 4.6 device with Desktop Manager 4.7. You can also purposely get this error by wiping your device clean using JL_cmdr or BBSAK.
I found the easiest fix to be just running the AppLoader.exe directly from Program Files -> Common Files ->Research In Motion –> AppLoader. Then plug in your BlackBerry into the computers USB cable and the second it says USB-PIN:Unknown you just click next to reload the latest BlackBerry OS you have installed on your computer.
If you are still having issues I recommend reading RIM’s article on 507 errors at this link. I once ran into the issue where my USB ports were set to power down to save battery life and it caused a 507 error every time using my ThinkPad.
FAQ: RIM Explains The Cause & Solution for 507 Errors During Upgrade
