Unable to connect to backend. HTTP error 0

Hey @marlenerice,

Which plugin are you trying to update? You didn’t mention in your request. Please let us know so we can provide you a solution.

Regards,
Mandeep

Hi Mandeep,

Ultimate Membership Pro. The whole package is 31.8 MB

Thanks, Marlene

Hey @marlenerice,

Thanks for getting back to us. Got to wp-config.php and change wp-debug to true. Please resolve all the errors you got after that. Also, check error logs in your server. It looks like you some PHP function error in site. It’s not a file manager plugin issue.

Regards,
Mandeep

Thanks Mandeep, also for your advice

Hi. I have the same error message ‘unable to connect to backend. HTTP error 0’ when I try to download files/folders with wp file manager plugin.

• This reply was modified 5 years, 8 months ago by Silvamayflower.

No replies yet, but to update: I updated php to 7.3, and was able to download one folder. However, this folder, dated 2013, is empty. This makes sense because the photos I uploaded and modified would most likely have been in 2014. Anyow, I tried to download 2014 and got same error message as above. Last night, I decided go into the folder, and upload all the photos in the one marked (1). Some 20 or so hours later, it is still sitting there, apparently ‘creating a file for download’ with 186 photos of various sizes waiting in the wings. In short, this plugin just isn’t working.

Hey @silvamayflower,

Thanks for getting back to us. Got to wp-config.php and change wp-debug to true. Please resolve all the errors you got after that. Also, check error logs in your server. It looks like you some PHP function error in the site. It’s not a file manager plugin issue.

Regards,
Mandeep

Sometimes this error occurs when, inside a page requested with HTTP protocol, you have a Javascript code trying to make an HTTPS request. And vice-versa.
If you are still facing this problem, press F12 (or Ctrl + U) and take a look at the HTML code of the page. If you see something like that in your code:

var ajaxurl = "https://mydomain.com/wp-admin/admin-ajax.php";

And your page was requested in a manner similar to:

https://mydomain.com/2019/09/13/my-post/#elf_l1_Lw

You certainly will face this error.