Output/Debugging: What does the exclamation mark mean and how to interpret it?

Question

When I turn on output and debugging I get an exclamation-mark in some cases (only in "templates"), like this:

What does this mean and how can I get more information about the error?

Thanks in advance!

Answer 1

The right answer is: exclamation mark means a LOG item. For your current log item (screenshot you provided), this log item register from system/ee/legacy/libraries/Extensions.php file.

So it register assets extension method that is calling on channel_entries_query_result hook.

In short, Nothing serious, Just a log message.