As a noob taking a training class, I have created a very simple sandbox solution in VS2010 with the VS2010 SP Power tools. The solution has one webpart with one button. It deploys to my site, the feature activates, but the web part does not show up in the gallery. I do not get any errors when I deploy and the webpart does have a SafeControlEntry. What would cause this, How can i troubleshoot? TIA Dean
I suspect that your Web-part might not be included in the feature you mentioned, have you checked that? If not, you can do it by opening the feature item in the solution manager of VS2010, your Web-part should be listed on the right under the "Items in this feature" list and not "Items in this solution". If not, double click it to send it to the right section.
If that's not the case, you might also want to make sure that you are looking in the right place while trying to add the Web-part. By default your Web-part should be listed under the "Custom" category. So assuming you are adding it from the edit mode of a SharePoint page in your browser you should first select the "Custom" folder from the categories on the left side of your page to view it.
Hope that helps :)