Ctrl+Z stopped working

Hello,

In one of my odt document in libreoffice, the function Ctrl+Z has completly stopped to work. When I click on it, nothing happen. I have probably done a false manipulation but I can’t figure out how to bring it back. Also, this happens only in one document. If I open a blank document and start to work on it, the function will work normally in this new document…

Please provide more info. Version of LO and OS. Is document readonly? Have you enabled macros and document contains macros?