I was trying to deploy a test application on to my WP7 device and kept getting a deployment error with the code “0x81030119”. Any deployment error code is usually caused by forgetting to have the Zune software open, or not reconnecting the WPConnect tool after previously having used the Zune software. However, the problem kept occurring and it turns out that the error code shows that I have reached the maximum number of side-loaded applications limit. Quick fix is to simply uninstall previously side-loaded apps. Anyway, to solve future code-related errors, the following table might be useful. (Note the descriptions aren’t necessarily the exact official error message, it’s been translated from Japanese).
Read more of this post