Thank you for the good description. We haven't encountered this issue before due to us not having encountered such large dashboards.
If you are using Sugar version 11.2.x or above, please download the 1.7.5 version of the package, which will extend the dashboard metadata from text (65 565 characters) to mediumtext (16 777 215 characters), which should be more than enough.
If you are using an earlier version of Sugar, please get back to us and we'll create a separate package for that version.
I have uploaded a new version of the plugin that supports up to 11.3. Version 1.7.4 of the plugin.
So try to install that version, do a Quick Repair & Rebuild after installation and then enter your Outfitters license key through Administration > SRD Runtime Filters > Settings.
Then you should be set.
Note that the plugin now requires that you add a "Saved Reports Chart Dashlet - Runtime Filters" dashlet Instead of "Saved Reports Chart Dashlet" to your dashboards to get the dynamic runtime filters configuration to show up in the dashlets, as they have added restrictions that do not allow us to upload packages that extend core functionality. Once you have added a report to a "Saved Reports Chart Dashlet - Runtime Filters" dashlet you should be able to scroll down and configure and apply runtime filters on the fly per dashlet.
Unfortunately, this issue may likely be caused by the receiver's email-server handling of the images, it might be that the recipient's email server is blocking the images.
Does this issue arise on a single contact or are there more contacts who cannot see the attached images?
If there are more than one, do they use the same email client?