Microsoft released service pack 1 (SP1) of Office 2010 late June 2011. Information on the update and download instructions are in their Knowledgebase article 2460049. The KB article was last updated yesterday.
Unfortunately, we and some of our customers have encountered problems after installing the update. While we haven't had exhaustive testing with SP1 and tentatively believe everything is okay with the 32 bit version, there are definitely compatibility problems with the 64 bit version of Access 2010. In particular, ACCDE files created in the original release of Access 2010 64 bit no longer run under SP1. This error message appears:
The database cannot be opened because the VBA project contained in it cannot be read. The database can be opened only if the VBA project is first deleted. Deleting the VBA project removes all code from modules, forms and reports. You should back up your database before attempting to open the database and delete the VBA project.
Obviously, with an ACCDE file, unlike an ACCDB file, you can't modify the VBA project. It requires rebuilding the ACCDE from SP1.
So far, we have not experienced problems with our 32-bit ACCDE files between the original and SP1 Access 2010 versions. Some of these issues have been noted in these articles:
Microsoft Access Development Team Blog: Using 64-bit Access 2010? You may want to wait on SP1
TechNet report: Access 2010 – Wizards not working after installing SP1
This is a Microsoft KB article discussing the problem which impacts ACCDE, MDE, and ADE files created with Access 2010, 64-bit. For us, when we create MDE and ADE files for use across multiple versions of Access, we've used Access 2003 so that still works fine. The only time we use Access 2010 64-bit version is when we're creating an ACCDE specifically for Access 2010 64-bit users.
This issue impacts two of our products' Access 2010 64 bit versions:
We have created new builds of these products and are undergoing internal testing and QA to verify they work with SP1. When ready, we'll release free updates of these products to existing customers. If you need it earlier, please contact our support team. Note that this does not impact the Access 2010 32 bit version.
Regardless of whether you are using our products or not, please be aware of the compatibility issues if you're using the 64-bit version of Access and deploying ACCDE files. You will need to make sure your Access version is in sync with your users' version. Unfortunately, this bug occurs before any of your code can run to provide instructions to your users or offer a graceful exit.
Not sure what version you have installed? Run Access, select the File menu, and click on Help. The version informing is shown on the right side and will show (SP1).