Hi,
I get the following error when there is a conflict in the appointments and one cannot view the project details. How to rectify this in the front end without rescheduling the appointment?

OwlError: An error occured in the owl lifecycle (see this Error's "cause" property)
    at handleError (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:916:101)
    at App.handleError (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:1543:29)
    at Fiber._render (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:941:19)
    at Fiber.render (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:939:6)
    at ComponentNode.initiateRender (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:1007:47)

Caused by: EvalError: Can not evaluate python expression: (bool((planned_date_end == False) and (planned_date_begin == False)))
Error: Name 'planned_date_end' is not defined
    at evaluateExpr (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:3031:54)
    at ProjectTaskFormRenderer.evaluateBooleanExpr (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:3034:8)
    at ProjectTaskFormRenderer.template (eval at compile (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:1501:374), :1006:28)
    at App.callTemplate (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:1164:129)
    at ProjectTaskFormRenderer.template (eval at compile (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:1501:374), :10:12)
    at Fiber._render (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:940:96)
    at Fiber.render (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:939:6)
    at ComponentNode.initiateRender (https://servicum-gmbh.odoo.com/web/assets/1295562/web.assets_web.min.js:1007:47)