Thanks Rashida.
I'm using Joomla Joomla 4.0.3 which is clear in the screenshot of the error, also the version number 4.0.3 is visible at the top of the screenshot.
There an issue with the Arabic Unitag language support. The dashboard shows that I have an update, it's Arabic Unitag, I install it successfully and the dashboard shows that there aren't any updates needed then a few minutes later the dashboard shows an update ready for Arabic Unitag.
I don't need the Arabic Unitag language so I tried to delete it (removed it from the languages directory and checked for it in the languages databse table.) but the issue won't go away.
Otherwise the site seems to work fine.