In particular I am looking for help with this error:
Also, why do I get this very unhelpful error when trying to attach an image?
"That image type is forbidden".
I have tried .gif, .jpg, .png, and .bmp.
The file size is less than 25 KB
If you have access to the Server machine(s), the logs in \data\tabsvc\logs\backgrounder folder usually have the full error.
For background tasks that fail, if viewing the associated Alerts it's true the error messages there are somewhat cryptic.
But if you then go to 'Background Tasks' under the Analysis section while viewing the Administrative views, the background tasks that were successful show as a blue dot. Those that weren't show as a red 'X' and if you hover the mouse over these the tooltip that pops up should have a more detailed error message than what was shown in the Alert.