Handling Multiple Users In Google Sheets
We apologize for this error. It's an ongoing bug in Google Sheets that Google is working on, but hasn't fixed yet. Here is how to get going again.
You need to be using Google Sheets as the default logged in account. To do this first select your profile photo on the top right of the Google Spreadsheet.
Now select the account with the word default next to it.
Now retry the operation you were working on before and everything should work. You may need to install the add on into this default account. If that doesn't work, you can also change your default account by following the instructions below:
Changing Your Default Account
Select your profile picture on the top right and choose "Sign out of all accounts"
Log back in with your desired default account by choosing the account from the list presented.
Complete the actions you were doing before with the new default account.