I installed KeePass2

sudo add-apt-repository ppa:jtaylor/keepass
sudo apt-get update
sudo apt install keepass2

and I copy plugin to KeePass to plugin KeePass folder and if I open KeePass I have this error:

Plugin is not loaded
A newer KeePass version is required to open this file 

Can you help me? I Use Ubuntu 20.04

2 Answers

You can try to use other PPA, it ships 2.48 version:

sudo add-apt-repository ppa:ubuntuhandbook1/keepass2
sudo apt-get update
sudo apt-get install keepass2

Temporary Manual Official Solution - 20.04

keepass2 PPA has not been updated for a quiet a while.
So follow the steps to update manually to Version 2.48.1 or latest

Download

Download portable version zip file from Official link

Unzip and copy the file KeePass.exe

Replace File

Close KeePass application if it's open
Open directory with admin rights /usr/lib/keepass2
Backup keepass2 Folder to safe place in-case things go wrong
Paste and Replace the KeePass.exe file to the folder

As of Version 2.51.1 you are good to go.