# Start up error - Uncaught Exception

**URL:** <https://discourse.nodered.org/t/start-up-error-uncaught-exception/42588>\
**Category:** General\
**Created:** [13 March 2021 17:18 UTC](https://discourse.nodered.org/t/start-up-error-uncaught-exception/42588 "2021-03-13T17:18:04Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [13 March 2021 22:39 UTC](https://discourse.nodered.org/t/start-up-error-uncaught-exception/42588/6 "2021-03-13T22:39:10Z")

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Does this pc have hyper v installed? It's know to block allocate ports.

Also what does `netstat -anb` report?

Follow this instructions in [this post](https://stackoverflow.com/questions/48198/how-can-you-find-out-which-process-is-listening-on-a-tcp-or-udp-port-on-windows) to find a process using port 1880.

Lastly, you could try starting node-red with a different port e.g. `node-red -p 18880`

Follow info

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