It works for me in hotmail. see screenshot I just grabbed a txt file from my desktop. Here is another pic with an image. It is a wittle touchy when dragging from laptop to external monitor, but when file manager is on the same screen it worked fine. Show the issue. What Desktop? X11 or Wayland?

Operating System: openSUSE Leap 15.6 KDE Plasma Version: 5.27.11 KDE Frameworks Version: 5.115.0 Qt Version: 5.15.12 Kernel Version: 6.4.0-150600.23.17-default (64-bit) Graphics Platform: X11 Processors: 16 × AMD Ryzen 7 PRO 6850HS with Radeon Graphics Memory: 62.1 GiB of RAM Graphics Processor: AMD Radeon Graphics Manufacturer: HP Product Name: HP EliteBook 865 16 inch G9 Notebook PC

Screen shots attached.

Manufacturer: Intel NUC13ANHi5 Operating System: Debian GNU/Linux 12 (bookworm) Kernel: Linux 6.1.0-23-amd64 CPU: 13th Gen Intel(R) Core(TM) i5-1340P Memory: 16 GiB of RAM Graphics: Intel® Iris® Xe Graphics Display Manager: LightDM XDG_SESSION_TYPE=x11 XDG_CURRENT_DESKTOP=LXQt

I haven't encountered this on Debian 12 with Mate DE and Firefox 129.0.1 64-bit.

I've always found the versions of Firefox straight from Mozilla to run better than the Official Debian builds so that could be relevant if you are using the latter.

I was using the Debian package of firefox-esr which is not very recent and it was crashing when connecting to a site with a MQTT feed. So I uninstalled it and installed the Mozilla repository to get the latest version.

That's when drag and drop broke, so I fixed one issue and created another by changing repositories.

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

If the new profile works, you can transfer files from a previously used profile to the new profile, but be careful not to copy corrupted files to avoid carrying over problems.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Try a different email service to verify. Provide steps and link to create a Roundcube Webmail account if it's free?

Created a new profile - same problem.

I have tried several web apps in addition to Roundcube that support dragging and dropping of files. They all have the same problem.

Okay. Time to go back to a previous version or ESR and test. If it works, post a screenshot Download, unzip, and run firefox-bin from the folder and see if you have the same issue. https://ftp.mozilla.org/pub/firefox/releases/

Could be OS / Desktop issue. Try your OS or another from a live usb stick and a different desktop.

Screenshot shows it working for me. Dropped browser link and image.

Also, how about those steps to sign up for a Roundcube Webmail account? I'm not seeing anything for a webpage, but just an app to install

Show the issue using other web apps and post links and screenshots so that I can try to replicate. Show what happens in Chrome or any other browser.

After watching this video I blame the app. You need to definitely show the issue using another "webmail" like gmail, yahoo, or hotmail. https://www.youtube.com/watch?v=y3Rnu0XB388

Even Comcast works. see screenshots

"Also, how about those steps to sign up for a Roundcube Webmail account?"

You do not sign up for Roundcube, it is server-side software:

Roundcube is written in PHP and can be employed in conjunction with a LAMP stack, or any other operating systems that support PHP are supported as well. The web server needs access to the IMAP server hosting the email and to an SMTP server to be able to send messages.

Roundcube Webmail is designed to run on standard web servers such as Apache, LiteSpeed, Nginx, Lighttpd, Hiawatha or Cherokee in conjunction with a relational database engine. Supported databases are MySQL, PostgreSQL and SQLite. The user interface is rendered in XHTML and CSS and is fully customizable with skins.

Roundcube is used by a number of universities to provide email services to students and staff. In a 2009 interview, two of Roundcube's core developers noted that the largest deployment to that date that they were aware of was at the University of Michigan with 70,013 students ''

Roundcube and my other drag and drop apps all function correctly in Chrome. I also verified that drag & drop works correctly within Roundcube (dragging a message from the message list to the Trash folder), so this is only an issue dragging and dropping between the Desktop and Firefox.

I need to install a different desktop and see if the issue is limited to Firefox and LXQt.

Right. That software is the issue. Do this. Create me an account and email me the password and link via this forum email service. I'll be waiting.

Wrong. I told you several times the problem occurs with multiple web apps supporting drag & drop.

There is a bug in Firefox for Linux v129.0.1 running on the LXQt desktop when dragging & dropping from the desktop to the browser.

Steps to reproduce the error:

I spun up a new VM and installed a clean Debian 12 Bookworm + MATE desktop. This includes Firefox v115.14.0esr. Tested drag & drop and it works fine.

Removed the firefox-esr package using apt. Also deleted the /home/user/.mozilla directory. Installed the Firefox .DEB Package for Debian per the instructions at Mozilla Support. This installs Firefox v129.0.1 Tested drag & drop and it works fine with the MATE desktop.

Install LXQt with LightDM as the default display manager (this is the MATE default display manager). Tested drag & drop - broken using the LXQt desktop. Changed the window manager from the LXQt default of xfwm4 to openbox. No change, still broken so the bug is with Firefox v129.0.1 running on LXQt.

I will report the bug to Mozilla.