title: Trying to write from R to Google Sheets, can't get credentials
body: <p>For the past 6+ months I read and wrote from R to Google Sheets without any issues, with the googlesheets4 package. Yesterday, all of a sudden, I started to get the 'Can't get Google credentials' error and I can't seem to find a solution to it.</p>
  <p>I've always used gs4_auth('email address'), no other details.</p>
  <p>I read the troubleshooting advice for gargle, I also found another thread here with suggestions, but nothing worked for me unfortunately. Here is what I get when changing gargle verbosity to 'debug':</p>
  <p>trying <code>token_fetch()</code>
  trying <code>credentials_service_account()</code>
  Error caught by <code>token_fetch()</code>:
  Argument 'txt' must be a JSON string, URL or file.
  trying <code>credentials_external_account()</code>
  aws.ec2metadata not installed; can't detect whether running on EC2 instance
  trying <code>credentials_app_default()</code>
  trying <code>credentials_gce()</code>
  trying <code>credentials_byo_oauth()</code>
  Error caught by <code>token_fetch()</code>:
  inherits(token, &quot;Token2.0&quot;) is not TRUE
  trying <code>credentials_user_oauth2()</code>
  Gargle2.0 initialize
  attempt to access internal gargle data from: googlesheets4
  adding &quot;userinfo.email&quot; scope
  Error caught by <code>token_fetch()</code>:
  ReadItem: unknown type 50, perhaps written by later version of R</p>
  <p>I don't have a clue what to change based on this info.</p>
  <p>I also read that this sudden error may happen if the cache where gargle saves authentication data is full. But I don't find the cache. I tried to run this:</p>
  <p>require(gargle)
  gargle_oauth_sitrep()</p>
  <p>And I get: Error in FUN(X[[i]], ...) :
  ReadItem: unknown type 50, perhaps written by later version of R.</p>
  <p>My version of R is 4.1.2 now, but before, it was 4.1.0. I updated it hoping it would solve something, but it didn't. I also reinstalled a few packages: curl, openssl, gargle. Still not working.</p>
  <p>I am out of ideas now. Can anyone help?</p>