No link to UCSC to visualise datasets

In Galaxy Europe, I have histories generated previously containing bigwig datasets that I was able to visualise in UCSC with no problem. But now, with the same bigwig files, I do not have the “Display at UCSC” link. I am not sure why this link is no longer present. Thanks for any advice.

@dgarrick please make sure you have a database associated. This is the genome identifier, e.g. hg19, mm10 or similar.

Yes they are hg38