When a dispatcher attempts to drag and drop a Service Appointment on the Gantt chart in the Salesforce Field Service (SFS) Dispatcher Console, the appointment moves back to its original position and the following error is displayed:
"Action Could Not Be Performed"
"Upsert failed. First exception on row 0 with id xxxxxxxx; first error: INSUFFICIENT_ACCESS_OR_READONLY, insufficient access rights on object id: [xxxxxxxxxxx]"
Here is the error in the browser HTTP Archive (HAR) logs:
This error occurs because the Service Resource object has incorrect sharing settings — specifically, the Default External Access is set to "Public Read Only" instead of "Public Read/Write."
The drag-and-drop failure on the Dispatcher Console Gantt is caused by insufficient sharing access on the Service Resource object.
The Resource Absence object has a Child-to-Parent relationship with the Service Resource object. When a dispatcher drags and drops a Service Appointment, Salesforce attempts to write to a Resource Absence record. This write operation requires "Public Read/Write" access on the parent Service Resource object.
If Service Resource is set to "Public Read Only" under Default External Access in the Organization-Wide Defaults, the write operation fails with the INSUFFICIENT_ACCESS_OR_READONLY error.
Please check the below screenshot for further references:
If the fix should apply to only specific service resources rather than all resources org-wide, you can use Sharing Rules instead of changing the Organization-Wide Default:
000394105

We use three kinds of cookies on our websites: required, functional, and advertising. You can choose whether functional and advertising cookies apply. Click on the different cookie categories to find out more about each category and to change the default settings.
Privacy Statement
Required cookies are necessary for basic website functionality. Some examples include: session cookies needed to transmit the website, authentication cookies, and security cookies.
Functional cookies enhance functions, performance, and services on the website. Some examples include: cookies used to analyze site traffic, cookies used for market research, and cookies used to display advertising that is not directed to a particular individual.
Advertising cookies track activity across websites in order to understand a viewer’s interests, and direct them specific marketing. Some examples include: cookies used for remarketing, or interest-based advertising.