When using Visual Studio 16.8.3 or 16.8.4, with Qt addins 2.6.x or 184.108.40.206, I have regularly an error with multiple process which seem to access to the same log file "moc.read.1u.tlog".
This error is also present in the last build 220.127.116.11 (generate after this bug fix
Here an exemple of the error:
Not that option "Parallel Process" is set to "Yes" on all Qt task (moc, ui, qrc). It's perhaps the source of this error.