Error Message - What does it mean?

[ProProjects]

Hello, My app has trouble loading today, "app did not load successfully. Please contact the app creator". 

I am getting this error, sometimes with the Staff table, sometimes with the Timesheets table in the details. 

Unable to fetch app definition. Error:Error: Data table 'timesheets' is not accessible due to: Visibility check was unavailable. Please retry the request and contact support in the problem persists.

Can anyone help enlighten so I can troubleshoot. Thank you. 

[a_aleinikov]

hi @ProProjects 

this error usually means appsheet can’t access one of your data tables — often due to permission issues or a broken data source link

things to check:

1. open Data > Tables and check if the “Timesheets” or “Staff” table has a red error

2. if you’re using google sheets, make sure the sheet exists and your account still has access

3. if it’s a database (like mysql), check the connection is active and not expired

4. try regenerating the structure of the table in appsheet (click the table, then “regenerate”)

5. if nothing works, try removing and re-adding the table

also, sometimes it’s a temporary google drive or connection issue — try again after a few minutes

[PauloExpert]

Hi! This error you're seeing — “Unable to fetch app definition. Error: Data table 'timesheets' is not accessible due to: Visibility check was unavailable” — usually points to a temporary data source access issue, particularly when using Google Sheets or Excel as your backend. Here’s a full breakdown of how to troubleshoot and fix it:

✅ Step-by-Step Troubleshooting

1. Check the AppSheet Data Source Connection

Go to AppSheet Editor > Account > Sources

Look for the data source (Google Sheets, Excel, etc.) your “Timesheets” or “Staff” table is using.

If you see a red warning icon or "needs authorization" — reauthorize or re-connect the data source.

2. Inspect Google Sheet Access

Open the "Timesheets" and "Staff" spreadsheet files directly in Google Sheets.

Make sure:

The file is still present and not deleted or moved.

It’s in a shared Google Drive (Team Drive), check that AppSheet has access to it.

If the file was moved or renamed recently, update its path or reselect it in AppSheet.

3. Check Sheet/Table Permissions

Ensure that your AppSheet account email (under My Account > Account Settings) has view/edit access to the sheet.

If you're using a service account or shared folder, verify domain sharing rules (especially if using Google Workspace).

4. Test Access to Tables in AppSheet

Open the App Editor

Go to Data > Tables > Click on the “Timesheets” table

Hit “Regenerate Structure” or “Test” to check if AppSheet can read the table now.

5. Check for Column Header Issues

AppSheet can fail to load if the spreadsheet:

Has merged cells

Has missing or duplicated column headers

Starts from a row other than Row 1

Open the sheet and make sure the headers are clean.

6. Clear Browser/App Cache or Try Another Device

If you’re testing from mobile, try accessing the app from a desktop browser (or vice versa).

Log out and log back in to AppSheet.

Clear your browser cache or use an incognito/private tab.

7. AppSheet Platform Status

Sometimes the issue is not yours:

Visit https://status.appsheet.com and check if there's an ongoing outage.

⚠️ Still Failing?

If the issue persists even after trying all of the above, do this:

➤ Capture and Send Logs to AppSheet Support

1. Go to Manage > Monitor > Audit History

2. See if the failed sync or load is logged there.

3. Take note of the Error ID or Timestamp

4. Contact AppSheet Support via support.appsheet.com

🛠 Quick Tip for Ongoing Reliability

Avoid moving files after connecting them to AppSheet.

Use Google Sheets stored in My Drive, not shared drives, unless absolutely necessary.

Regularly backup your app and sheets.

[jerrygen]

Hi,

The error message you're seeing—"Data table 'timesheets' is not accessible due to: Visibility check was unavailable"—usually indicates that AppSheet is having trouble accessing the data source for that table, possibly due to permission issues, expired credentials, or a temporary service disruption. Since it affects both the Staff and Timesheets tables intermittently, it’s likely related to connectivity or authorization with your cloud storage (like Google Sheets or Excel). Try refreshing your data source connection, checking sharing permissions, and verifying that the tables still exist and are accessible. If the issue continues, contact AppSheet support.

Regards