I get an error message during download in the Freescan that says "Unable to set WX", and "No APCO band plan available for MidlandCnty", when RadioReference shows that my systems are APSC 25 systems.
Those are common FreeSCAN error messages, and can be ignored.
It's telling you that you that you did not set up weather details on the Set Up Scanner drop down menu.

That's not required for normal scanning, and does not affect whether you can scan the channels you program.
As for the APCO band plan for the system, that's not required either. While there are a few system types that do require that plan to be programmed, that does not apply to
MPSCS, the trunked system used in your county. The band plan information is carried on sites control channel frequencies & when receiving a site, the needed information will flow into the scanner with no need for you to enter the data.
As for not being able to scan a trunked system, it's likely that you did not program everything needed. One of the most common errors is only programming the talk groups, used by the various agencies in your area, but not entering the sites used for transmitting. That's what
jt was commenting on. Look at the "Uniden DMA scanners section" section on this 'Nothing to Scan'
page in the Wiki.
Attached is a file I created for your county in FreeSCAN. It's 'zipped' (compressed) as that is required to attach a FreeSCAN file to a post. Save the file to your PC then use Windows Explorer (also called 'File Explorer in some versions of Windows) to extract (unzip) the Midland County file then open it in FreeSCAN. I don't know what, specifically, what you are most interested in, so I imported all the public safety agency talkgroups in your county. You, of course, can delete or lockout those not of interest.
There are a couple of talkgroups listed, for your county, that are labeled as "encrypted". Those will be ignored by your scanner, idf encryption is in use, without you having to lock them out or delete them. Those are indicated by
DE in the mode column.
These is a
User Guide for FreeSCAN in the Wiki. Since you are a premium subscriber, you an import exactly what you want from the RadioReference database into FreeSCAN.