I'll post the solution I got on the support chat that worked for me :
First I got to ~.ryzom/user , there was a file widgets.xml which was empty. I deleted the file and run client once again, it got recreated and the problem wanished.
First I got to ~.ryzom/user , there was a file widgets.xml which was empty. I deleted the file and run client once again, it got recreated and the problem wanished.