Error: Line 1 - This is not a valid log file. Bad line was

So when I try to upload my header on my log file looks like below, I compared it to successfully uploading log file, I have tried replacing the content from a good log, and I have compared it to guild members. What is going on here and how can I fix it? I opened the log in notepad++, and I have content in there.

Bad line below
7/30 16:15:30.747 COMBAT_LOG_VERSION,14,ADVANCED_LOG_ENABLED,1,BUILD_VERSION,8.3.7,PROJECT_ID,1