Suggestions :
1) download and install nightly
2) create a new static lib project (of the irrlight type) , start with adding just 1 file and see if it builds fine. Then compare manually the 2 cbp files, just xml, some things have changed. After the environment, compiler, linker options are done, well you could copy/paste all those Units (the actual source files) and see if still works. If it already fails with the small project with 1 file, things might be easier to spot.