Hello!
UltiDev Cassini does not have logging capabilities, but to troubleshoot problems like the one you are having the best tool is
Fiddler. Simply run Fiddler on the same box where your browser is, and if your application is on the same box - make sure you access it using machine name or real IP address instead of localhost and 127.0.0.1 - this way Fiddler will intercept all HTTP traffic and will give you clear picture of why some of your requests fail.
Please let us know if this has helped.
Best regards,
UltiDev Team.
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