An error occurred in Eurekalog's user event handler. [Accessviolation] Access viloation at address 00000000044669CD
By "Signing In", do you mean connecting to a database or just starting Toad?
If the former, does it happen on every database? Does the connection get made and then it errors while auto-opening some window?
If the latter, can you post a screen shot of the splash screen so we can have an idea of how far along it go?
Did this just start or has it been happening for a while.
The more information you can provide from the start, the better. Please don't make us guess. Thanks. 
Connecting to the Database. This is a new installation, before there was a different message, but no this one.
Did you have an older version of Toad installed before this, or is this the first time you've installed Toad?
There was an old version installed, but we uninstalled it first before we install the new version.
Maybe some of the settings from your old version of Toad are still there and causing this.
Try this:
Start Toad.
Do not connect to a database
Follow the "Reset Toad's User Files" steps here
Will give that a shot and let you know. Thanks
Unfortunately that didn't fix the issue. Resetting Toad's user files.
I'm sorry, I don't have any ideas except try 13.3 if you can. You might want to get with Quest Support on this one.
There was something similar reported recently by a user with 13.3...problem started when Windows Security Exploit Protection policy changes were made. At first, the user thought it was due to a Windows 10 update. Toad 13.3 Eurekalog's user event handler
Could it caused the old version of the software? as the 12.2 folder still there.
unlikely. I have a virtual machine with almost every version we've ever released installed on it.
I'm not aware of any problems with specific Oracle client versions, but since it happens when you try to connect, you could try removing your Oracle client and installing a newer version.
Does it happen no matter which database you try to connect to?
Also, you said "before there was a different message". What was the message that you saw before?