The ID you see in the "System ID" field is not the SID that Unitrunker wants.
If you want to download a system by its System ID, leave the SID field (the one at the bottom of the system page) blank, and fill in the top two lines of the system page: Type and ID. In your case, if you want to download AWIN, Type is APCO P25 and ID is 188. (The program will change it to "00000-188" when you cursor down, but that's not a concern.) When you download with that setting, the program will create AWIN (BEE00-188) in your Systems list. (Or it will update the existing system entry if it already exists.)
The value at the bottom of the system screen in Unitrunker is the SID, which is a unique number given to every system in RadioReference's database. By entering 188 in the SID field, you are asking it for the system that RadioReference knows as 188 - which is the Baltimore City trunk. If you go to the page for AWIN -
Arkansas Wireless Information Network (AWIN) Trunking System, Statewide, Multi-State - Scanner Frequencies - and look at the address bar of your browser, the URL for the page ends in "sid=3918". That's the value you put in the SID field of Unitrunker. However, you can only use one or the other - either put the SID in and leave system type and ID blank, or leave the SID blank (or zero) and put in the system type and ID.
EDACS systems don't have system IDs, so you can't download them using the top two fields. You have to enter the SID. So for example, if you wanted
American Electric Power (AR/LA/TX) Trunking System, Various, Multi-State - Scanner Frequencies - you would enter 783 (look at the address bar in your browser) in the SID field and download that way.
Note that Unitrunker doesn't consider a field filled in until you leave it. So once you type in 783, you have to move your cursor off that field into another one (just hit arrow up or arrow down). Then you can download using that SID.
