Back in September I mentioned similar problem to what I am experiencing now, with one project. An error deleting temporary log files causes the log file contents to be deleted and replaced with this message. On this occasion, Therion seems to be compiling just fine, but I have no (meaningful) log file! "C:\Program Files (x86)\Therion\therion.exe: warning -- error deleting temporary directory -- C:\Users\Bruce\AppData\Local\Temp\th7916" The temporary folder contains a single file like data.1 attached. This is only an occasional problem. Mostly I get a valid log file, but it does seem to be persistent with some projects and not others. What I would like is for the above message to be appended to the log file, and not replace the contents of the log file. Therion 5.4.1+e7e9d34 (2017-12-14) Bruce