After upgrading from WebCenter 12.x to WebCenter 14, any Excel lists used in attribute categories may not function anymore due to a missing driver. Previously, the Excel lists functionality used a 32-bit driver, already installed on your Web Server. WebCenter 14 however, requires a 64-bit driver, possibly not available on your system yet. To correct the problem, you will need to download and install the 64-bit Excel driver on your WebCenter Web Server.
Provided you have Excel lists uploaded to your WebCenter Web Server, you will see one or multiple error messages when you try to open any Attribute Category to edit it. The error message states that the Excel list(s) could not be loaded.
To be able to continue using your WebCenter 12.x Excel lists in attribute categories, you may need to install the 64-bit Microsoft Excel driver on the Web Server.