...If not trying at the same PC B4J compiling.. may be need runtimes of .net 4.5+ ...better 4.8...
and the most important... at pc compiling - do have installed OpenJava ? (
Recommended: OpenJDK 11 + OpenJFX 11:
download link. )
and ofcourse configured at:
Tools > Configure Paths.
read "Installation" here:
https://www.b4x.com/b4j.html
... If not having errors as you are saying... it seems problem with directories + reading files from them ---> try using file.dirapp and target to the right paths... for start target at specific directories to see if pass the errors... and try to fix with file.dirapp/dirdata/assets... have in mind file.combine...
have in mind is better using slash like linux/unix... for example "c:/b4j/projects/temp"