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This may be because you are using an invalid or revoked access token in your business rule. Make sure you are using a valid access token and retest.

This error can also occur if you are writing to a Google Sheet using a business rule, and you have a text or textarea control that gets a value with a comma at runtime. For example, if you are passing a control in the var updateparams rule such as "FullName" and the runtime value entered is "Smith, John" the comma can interfere with the comma-separated update parameters being passed to the Google Sheet. This will be fixed in a future release. A workaround is to add code to your rule to strip the commas:

//Remove Commas
  var t = FullName.value;
  var tcomma = t.replace(/,/g," ");

Then, pass the variable "tcomma" in the updataparams rule instead of the original control value. 

Internal Server Error

You may encounter this error when performing read/update/write operations to a Google sheet from a form/flow. The Google API can never be a replacement for a database in terms of reliability. There are no SLAs associated with free google accounts. makes multiple http calls to the Google API with no guaranteed SLA.  As the load increases, the chances that the Google service might fail increases. If you encounter the 'internal server error', the only thing to do is to try again later

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