How to restrict users from uploading large file as attachments
How to alert the user when attaching files greater than 10 MB?
Add the following parameter in prconfig.xml file:
<env name="Initialization/MaximumFileUploadSizeMB" value="10" />
With this parameter configured, the alert message given below will be displayed:
Also, refer the PDN article: https://pdn.pega.com/troubleshooting-cannot-close-error-message-window-oversized-file-attachment