Error Code 403 when trying to process an .ics file stored in Google Drive

[PH1TCH]

First of all, thank you very much for this awesome script 🥳

When trying to get a .ics file from Google Drive using a link that looks like this "https://drive.google.com/uc?export=download&id={id}", it works but it also fails every now and then and shows the following error message:

05.05.2022, 11:13:01	Error	Exception: Request failed for https://drive.google.com returned code 403
    at [unknown function](Helpers:80:37)
    at callWithBackoff(Helpers:877:16)
    at fetchSourceCalendars(Helpers:79:5)
    at startSync(Code:156:21)

Seems like Google is blocking automated requests, see this and this

A solution could be to use the DriveAPI instead of UrlFetchApp but I am not sure about this.

Are there maybe other solutions to download and process the file consistently?

Many thanks in advance!

[derekantrican]

"403" is "Forbidden". Can you check to make sure that file is shared in Drive as "Anyone with the link"?

[PH1TCH]

Yes, the link is set to "Anyone with the link". As I said sometimes it works but it fails occasionally with a 403 error code.

[ersaxton1]

I am having the same issue on a calendar of mine, but my error is coming from the website that produces the calendar (not google). It only happens 5-10% of the time. But when it does happen, it deletes all the events in the calendar. Is there a way to force a stop if that error is produced? The log shows that it gets this error 3 times and then proceeds to sync a blank calendar (erasing my entire calendar). I wouldn't even mind if the sync stops after the first error.

[jonas0b1011001]

Is there a way to force a stop if that error is produced? The log shows that it gets this error 3 times and then proceeds to sync a blank calendar (erasing my entire calendar). I wouldn't even mind if the sync stops after the first error.

You can add a check in code.gs line 160 to skip the sync if there is no valid source calendar.

if (responses.length == 0){
  return;
}