I use the Graph Paper Press theme Photo Workshop 1.0.5 with the domain MariusCoetzee.com and was recently having problems getting Photoshelter to “Match Your Site to Your WordPress Blog”. It kept giving the me the error “We were unable to find a compatible theme at the URL you requested. Please check that you have the
most up-to-date theme version.”
I fixed this issue by disabling the W3 Cache Plugin, which was altering the code that Photoshelter was grabbing when it runs its generator, hence the error.
Once disabled I re-ran the generator and it was able to update my Photoshelter site to match my WordPress blog. Also just make sure that when you run the generator, rather than using your homepage URL (www.mariuscoetzee.com), you use the URL of an actual page – even your About page would work (www.mariuscoetzee.com/about/).
I hope that is helpful! If you need any further clarification here, just let me know.