Earlier in the day, the official Twitter account shared that they were investigating,
“We are currently investigating an issue with LOTRO Market purchases not delivering. Once our work is complete, we expect these purchases to begin being delivered. We will keep you updated. #LOTRO”
There were a few Reddit threads like this one which shared the inability to purchase the expansion. Yet another Reddit post documented being kicked off and being unable to log back in, indicating that game worlds had gone down. Some time later, the Twitter account posted that they were working on restoring everyone’s purchases after the Market came back online.
Their most recent tweet confirmed that any overnight purchases which didn’t deliver have now delivered,
“Purchases made overnight and today from the new LOTRO Market that failed to deliver have now been delivered. #LOTRO”