This recent article makes it very clear:
Whereas Chabad Lubavitch was very much distancing itself from any kind of Christians, now the chassidic group does more and more participate in various Christian activities. A while ago I wrote about Chabad Shlichim in Germany participating in community gatherings with Christians. These Shlichim apparently think that in Germany, Jewish communities have to be on good terms with local Christian church communities.
A Jerusalem Chabad House receives Christian visitors. This was the main reason why I had left a Chabad Pessach Seder this April. I paid a lot of money for my ticket and then I saw Christians streaming in for free and mooching around. This was so disgusting and I didn’t know that Chabad Lubavitch has sunken that low. Afterwards I spoke to the Shaliach and he told me that he won’t let any Christians inside. And sure enough, soon after, his place was full of Christian visitors again. I was so upset that I just left before the meal had even started. I didn’t even think about the 250 Shekels anymore but just wanted to get out of there.
Five years ago, a Chabad hostel let in a Christian and instead of giving Shiurim to the Jewish guests, the Rabbi was only sitting together with the Christian trying to explain to him why Christianity is wrong. I got the impression that maybe money donations do play a role but I may be wrong.
If the Rebbe was still alive, he would be furious!