https://bugs.winehq.org/show_bug.cgi?id=50014
--- Comment #4 from Roman Pišl rpisl@seznam.cz --- My experience is that the warning message often appears when there is an error during startup and interacting with that dialog may also break the whole installation badly, so I rather start from clean wine prefix and new conemu installation.
I also had to clean build dir completely during latest git bisect, there were probably some modifications to the build system recently.