Originally Posted by InADream
Just upgraded to 188.8.131.52 & I cannot find the desktop software to match... I keep getting the error message when trying to upload ALX files... It says no Additional applications blah blah blah
So, you actually upgraded your BB's OS? Any Desktop Manager will work. 4.2 SP2 is what I recommend but DM 4.3 will work too. You don't "match" the OS's and the DM.
Follow NJBlackberry's instructions above and all will work. Install both again and follow his instructions in the exact order.