Enterprise Vault for Exchange: Office Mail App (OMA) does no longer initialize

Enterprise Vault for Exchange: Office Mail App (OMA) does no longer initialize

Article: 100048648
Last Published: 2020-10-19
Ratings: 3 0
Product(s): Enterprise Vault


All of a sudden the Enterprise Vault Office Mail App (OMA) from Outlook Web Access (OWA) no longer loads properly, instead the banner contains 'This add-in has been disabled to help keep you safe. To continue using the add-in, validate that this item is hosted in a trusted domain or open it in the Office desktop app.' 

Error Message

after having clicked on CONTINUE the 'Sorry, we can't continue' appears


The aforementioned occurs with recent version of browsers such as Microsoft Edge or Google Chrome and only when Enterprise Vault OMA is initialized in OWA.

While loading the Enterprise Vault OMA the browser checks Microsoft content delivery network (CDN) like explained in this article; the recent updates on such CDN have caused third parties add-ins to no longer load properly.

This Microsoft article explains the vulnerabilities fixed CVE-2020-16969

As a temporary workaround it is possible to use legacy Internet Explorer which does not appear to be sensitive to the updated CDN.


In order to have the add-in properly working (Enterprise Vault and any other third parties add-ins) it is required to install the KB4581424, however this is available only with specific Exchange Cumulative Updates, consult the Enterprise Vault Software Compatibility List to make sure a supported configuration will be in place.

After the installation of the aforementioned KB the same error will still be encountered like:

However clicking CONTINUE it will ask to add the Enterprise Vault domain as a trusted domain for the app:

and after having refreshed the page Enterprise Vault OMA will finally load properly


Was this content helpful?