I just upgraded to WP 4.9.5 I get the same error. Plus I cannot add new users from the Super Admin account. What gives?

Any news on this one? I see exactly the same error on WP5.1.1MS

This is still an open issue from what I can tell.

Not sure what happened with it but the lastest official word I've received on this can be found on this thread.

Hope this helps.

@crazycoolcam I'm working on this for the next release, and wanted to ask about your experience with the patches in the past. Do you only apply manually the user-new.php patch after it failed, or do you patch all the files manually?

I ask because the instructions I see for the wp-login.php file don't seem to match what the patch is doing, and I was wondering if you have experienced any problems with the signups. If not, then the patch is most likely fine, and the instructions a bit outdated only.

I look forward to your input. Thanks! :)

Hi Cristián,
I generally like to use the automatic patch, and will only manually patch it when it has failed. When manually patching, I will look at the intent of the patch (adding a filter or something to that effect), and then add it into the file using whatever the latest formatting is for that line (or lines) of code. I've noticed two or more changes to the formatting of the line in question.

I'm not exactly sure what the patch does, but I suspect it has to do with allowing tasks (likely levels and/or capabilities) to be immediately added to users on their registration.

I've not noticed any problems with signups, but I also don't get signups very frequently. (My site is multisite, but not a blog-farm. I use one or two user levels, but mainly custom capabilities.)

Let me know if you have any other questions.

~Cam

Gotcha. Thanks! :)