OUTER MAIN LOOP ERROR: Selected screen mode not avail!!
This is a fairly common error that is simple to fix.
You need to check that you have the very latest video and VESA drivers from the manufacturer of your video card. In almost every case this error is caused by not having the latest VESA driver.
You can also try using the universal VESA driver included on The Settlers II CD, in the /UNIVBE directory.
If you are using a newer version of the Universal VESA driver (anything after version 5.1), try the following switch while loading the driver: uvconfig -L0 -V (this disables the linear frame buffer), and may work on many cards that do not normally support the VESA mode in the game.
If you are using a newer version of the Universal VESA driver, please try the older one on the CD. There are some problems with The Settlers II that have been reported with the newer versions of this driver.
If you own a Matrox video card, please contact Matrox to get the latest flash BIOS upgrade (version 2.20 at the time this was written). They will send this to you on a disk. You can also get it electronically from CompuServe or from Matrox's ftp site:
ftp.matrox.com in the /pub/mga/millennium directory.