I'm having the same issue. Add-ons in production have begun to return this error.
The add-ons use the V8 engine.
The sidebar won't even open.
From logs I see:
resource: {
labels: {
function_name: "showSidebar"
invocation_type: "menu"
project_id: "********"
}
type: "app_script_function"
}
severity: "ERROR"
timestamp: "2024-10-16T12:07:30.950Z"
showSidebar function:
SpreadsheetApp.getUi().showSidebar(
HtmlService.createTemplateFromFile('sidebar.html').evaluate()
.setSandboxMode(HtmlService.SandboxMode.IFRAME)
.setTitle('ABCD'));