Do I have first hand experience - certainly, lots in several non-european countries in addition to the UK. Regarding a language barrier, in one particular country my wife and I made friends with and were conspicuously well treated by local people of a very different culture, we initially spoke none of their language and many of them spoke no English at all. I kept in touch with some of them until a conflagration there cut off telephone communications. While there we initially met and mixed with other expats, nearly all of whom were British and all of them were decent people, but we became increasingly tired of the rather predictable drink/banter culture and eventually gave up on it. We miss the local friends more than any of the expats and are distinctly uncomfortable not knowing if they are still in their country and indeed whether they are alive or dead.
In my opinion this is very much about whether strangers are prepared to give each other the space to be different as opposed to insisting on copying of ways in order to be accepted. In a way I understand why some find at least odd the maintenance of conspicuous difference, generation after generation, but I cannot get too worked up about mostly visual things - what goes on in another's mind you will never know and should avoid guessing at it. Someone meticulously avoiding consumption of alcohol is to me no measure of the person, but I realise that to many alcohol is central to all socialising and not being able to get past that is to me their problem.
Civil war conditions excepted, I have experienced more overt unpleasantness directed at me personally within Europe than outside it (but tiny in total and always at first total-stranger contact), and that also goes for conspicuous kindness - as a result I am convinced that other parts of the world have just as high a percentage of nice people. And before anyone puts two and two together to make five, my appearance indicates that I am very obviously a "Caucasian".
Sadly, prejudice and worse will probably never disappear although it is distinctly a product of insecurity and mistrust, both innate and induced. It is interesting to note that those who have received the most enduring admiration, nationally and internationally, are probably exclusively people and their initiatives that removed such barriers.