Steps to reproduce:
After upgrading Zabbix from v6.4.7 to v7.0.0, I cannot edit any of my past plain text dashboards (which should now be item history as per https://www.zabbix.com/documentation...n-text-widgets), I get directly Unexpected server error. I tried also recreating the dashboard but when I choose the item in Columns and click add, I get immediately the same error. Also checked the zabbix server logs but there's nothing there regarding this. Can you please advise if there's any way to fix this ?

 
Result:

See screenshot