Chrome DevTools won't let me set breakpoints on certain lines

Question

In the image above, I tried setting breakpoints on every line from line 437 to line 443. However, I cannot set breakpoints on lines 439 and 440. When the function runs,

Answer 1

I have same problem in chrome dev tool source panel snippets when I write some codes to test my idea.

Only way for me worked is close dev tool panel and refresh page then reopen

This problem happened after I modified codes in debug mode

Answer 2

I think that my classmate and I had this issue as well today. We made our changes and then hit Ctrl + S (or Cmd + S) to save the changes in the debugger and then we were able to add the breakpoints.

Answer 3

This was frustrating for me today but I found the problem. I was trying to place a breakpoint inside an orphan function (nothing was calling it). As soon as I fixed it, all was well. Smart - but wish there was even a tiny hint that this was the case.

Answer 4

If you are using js minification and sourcemaps, ensure that they are up to date with your source code.

Answer 5

This recently became an issue for me, running System.js and Babel, and with plain ES6 transpiling, I haven't gotten to minifying/mapping yet. A workaround seems to be to add your breakpoint to the !transpiled file, a matching breakpoint will automagically appear in the corresponding line in the raw file.

Answer 6

In my case, I could not put a break point on the calling function line, but it worked into the function... weird but at least it works.