How to fix texture overlap?
I got the Muelsfell Dungeon Crawl Display Base and the left wall has overlapping texture:

When using a different shadder it has the same issue. The third image in the shop: http://www.daz3d.com/muelsfell-dungeon-crawl-display-base shows the same problem so it isn't just my PC. Is there a way to fix this?

Comments
It's a seam issue from how it was UV mapped...
Submit a bug report
https://helpdaz.zendesk.com/hc/en-us/requests/new
Either the maps will need to be blended across the seams, in a 3d paint program or the wall needs to be remapped to move the seam to an edge, where it will be less noticeable.
Ok thank you. I have sent a bug report.
Depending on what your scene is, perhaps a workaround would be to set one or more other objects on the top of the wall or between the camera and the seam to disguise it. Possibly you could even apply the material, or a photoshopped version of it, to a primitive or other object that you could set on top of the seam but also rotate so it's own seam isn't visible at the same time it hides the layer below it.
I was hoping for a lasting solution. Possible with blender or similar but my knowledge in that concern is very limited. I will try to export it into blender and see what he says.
Sorry, I just now saw this thread. Last month, I was told about this problem by Daz, updated the problem textures, and sent them in so this should already be fixed. Apologies, it was just an oversight during the creation process.
You should see a product update in the install manager available, or you can just redownload from your purchase history. Hope the fixes address the issues you were having!