I was having this problem, but I finally got it to run. (Win 10)
I uninstalled EQ steam client, and also uninstalled Steam.
Rebooted, ran CCleaner utility's Registry "Scan for Issues" and "Fix Selected(ALL) Issues".
CCleaner Free Utility Download from the official site:
https://www.ccleaner.com/ccleaner/download/standard
Rebooted, reinstalled Steam. Made a new steam Library directory. Added EverQuest Free-to-Play from Steam STORE.
When it was added to my Steam LIBRARY, on the left I right-clicked to open the game properties.
I unchecked "Enable the Steam Overlay while in-game" and unchecked "Use Desktop Game Theatre while SteamVR is active"
As soon as the steam eq client download was complete,
THINGS I DID NOT DO:
I NEVER RAN THE GAME "EverQuest Free-to-Play" FROM STEAM
and NEVER RAN THE DEFAULT PATCHER "LaunchPad.exe"
I went back to game properties in Steam Library >Local Files (TAB) > BROWSE LOCAL FILES
Opened the install directory. ALT+UP_ARROW or navigate to the parent directory
(example)Mine was "D:\SteamLibrary2\steamapps\common"
I copied the Everquest F2P folder to a different directory
(example) "D:\Games\SOD"
Downloaded the latest SoD Patcher from
https://shardsofdalaya.com/files.htm
Placed it in "D:\Games\SOD", and right clicked on the file, selected properties > Compatability (TAB)
Checked "Run this program as an administrator"
Clicked "Browse" by the white bar for "Everquest Directory"
Navigated to my copied Everquest F2P directory
(example) "D:\Games\SOD\Everquest F2P"
Checked "Repatch All"
Let the patch run, the CLOSED the patcher
Ran OptionsEditor.exe from the game directory. Clicked through some random settings until it closed.
Ran SOD Patcher again
With Repatch All unchecked > (clicked) Patch and Run
After load > (clicked) Run Game
Worked
Every step I described here may not be necessary, but this is how I was able to get it to run after suffering that same issue