Hello @daveinhull, I'm using 1.8.14 and works ok, roll-back was the solution for me, try it and tell us.
This looks like an encoding problem.in fact if ESPAlexa v2.7.0 is installed under arduino and if Espalexa.h, EspalexaDevice.cpp, EspalexaDevice.h are removed in B4R directory rEspalexa, compilation is OK with B4R
i will make a new delivery of rEspalexa v2.7.0 in this way, but i don't understand why compilation is NOK when ESPAlexa library is in rESPAlexa directory.
This looks like an encoding problem.
Remove the BOM identifier ( Byte Order Mark) from your source codes. ( see details: https://en.wikipedia.org/wiki/Byte_order_mark)