Script lab custom functions feature does not work

Question

When I try to access script lab custom functions feature I am greeted with message. Script lab -> funtions So the issue is not even in some particular function, the whole feature does not work.

Error:
{
    "stack": "RichApi.Error: There was an internal error while processing the request.\n    at new n (https://appsforoffice.microsoft.com/lib/beta/hosted/excel-win32-16.01.js:26:235928)\n    at n.o.processRequestExecutorResponseMessage (https://appsforoffice.microsoft.com/lib/beta/hosted/excel-win32-16.01.js:26:299150)\n    at https://appsforoffice.microsoft.com/lib/beta/hosted/excel-win32-16.01.js:26:297255",
    "message": "There was an internal error while processing the request.",
    "name": "RichApi.Error",
    "code": "GeneralException",
    "traceMessages": [],
    "innerError": null,
    "debugInfo": {
        "code": "GeneralException",
        "message": "There was an internal error while processing the request.",
        "errorLocation": "CustomFunctionManager.register",
        "statement": "v.register(...);",
        "surroundingStatements": [
            "var workbook = context.workbook;",
            "var v = Microsoft.ExcelServices.CustomFunctionManager.newObject();",
            "// >>>>>",
            "v.register(...);",
            "// <<<<<"
        ],
        "fullStatements": [
            "Please enable config.extendedErrorLogging to see full statements."
        ]
    },
    "httpStatusCode": 500
}

Answer 1

I've had this issue. I think I've seen there are differences between 2019 standalone and Office 365 subscriptions and the office js scripts that run. In my case, I was logged into a 365 enterprise subscription which reproduces the same error described. So what I did as a work-around was simply log out. And then register the function, and then log back in again. The registered function continues to work after log in.