I realize this isn't for Rohan but you can try the following tip:
I do my gaming on a high resolution monitor (2560 x 1440) and normally have to set my font scaling. This can have unexpected side effects in games Like Rohan and Seal.
You can force Windows 10 to disable changing font sizes for applications using the compatibility properties. The example is for the Rohan launcher, but it should work equally well for the Seal.
I would strongly suggest looking into your client install directory to find the actual seal client .exe file that the launcher runs and set its compatibility as well.
Try out those settings and see if it makes your game a little more playable.
/Cheers
@amalager : Seal came out before WIndows 8 and 8.1 as well.![]()