Here is the error message displayed for one of the applications after I enabled Failed Request Tracing in the IIS server:
Cannot add duplicate collection entry of type ‘add’ with unique key att...
Published Nov 05, 2020
Version 1.0
Blog Post
I have this same error but in a different context. The duplication is not in web.config but in
windows/system32/inetserv/config/applicationHOST.config
You must logged in as an Administrator to see this file
I have seen several or many solutions when it is in web.config, too many for me to start messing with, so looking for suggestions 🙂
Here is a pic of the duplication...
[BTW, I see no SAVE button anywhere on my screen, and when I clicked Preview my post disappeared, came back on Exit Preview]
Thank you,
Mick