This issue can be caused by multiple factors and each factor is covered in a separate section below:
More than one data source is selected within Access Digital Tax.
The browser being used may not be compatible, or not up to date.
Not all 9 boxes have been correctly assigned to a cell in the spreadsheet file
The machine is missing the registry keys which determines if a browser supports the file type.
1) Multiple data sources selected
In Access Digital Tax, to amend the data source, in the bottom right, see Account Details.
Next to Data Source(s), click the Edit pencil icon. The Edit Data Sources window appears.
If the data source has been selected, a tick will cover the icon.
If there are multiple Data Sources selected, to de-select the incorrect Data Source, click the Data Source(s) to be de-selected. Options appears in the bottom half of the window.
Next to the incorrect Data Source, select the check box. This will remove the selection. If there are more than 1 with a check box next to them you will need to uncheck all of them, if you do not then the "Tick" will not uncover the data source icon.
Click Save. This will have removed the incorrect Data Source(s) and the 'Next' or ‘Submit’ button will no longer be ‘greyed’ out.
2) Incorrect Browser
Ensure to use one of the compatible web browsers following: Google Chrome, Mozilla Firefox, or Microsoft Edge, for Access Digital Tax.
The chosen browser should also be kept up to date on the latest version currently available.
3) File Upload
When uploading a file, ensure each box is matched up and assigned with a cell within the spreadsheet. For guidance on this, please refer to Access Digital Tax: How to Submit a VAT Return in Evo using an upload file
If uploading an Excel workbook then ensure that it only contains the single spreadsheet containing the VAT figures. If there are "workings out" then these can be kept in another Workbook and then it can be linked to from the first if required.
4) Registry Keys are missing
To fix this issue it is highly recommended to get your IT to follow the steps below and make changes to your computer.
This issue can be fixed by populating the Windows registry with the correct MIME type for 3 file types. They can be found in the following locations:
Computer\HKEY_CLASSES_ROOT\csv
Computer\HKEY_CLASSES_ROOT\xlsx
Computer\HKEY_CLASSES_ROOT\xls
You will need a String in these locations which corresponds the following key/value pairs:
Computer\HKEY_CLASSES_ROOT\.csv
Name: (Default) | Data: Excel.CSV
Name: Content Type | Data: application/vnd.ms-excel
Computer\HKEY_CLASSES_ROOT\.xlsx
Name: Content Type | Data: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Name: PerceivedType | Data: document
Computer\HKEY_CLASSES_ROOT\.xls
Name: Content Type | Data: application/vnd.ms-excel