When searching documents in openarchieven.nl you normally see checkmarks appearing next to documents recently viewed.  In the past week or so those have disappeared.  I don't know if I did something to cause this, but another user mentioned the same issue on October 22.

Can you please fix or tell me what I need to do to fix this?

Thanks!

I can confirm this. Unfortunately, the owner of OpenArch is the only person who can resolve technical issues with the website. He hasn't been around for the past two years and doesn't respond to any issues mentioned in the forum. However, he does work on the website in the background. So, you can only hope that it gets fixed someday.