Few days ago I met strange problem with webpart during work with SharePoincie 2013. I cannot get access to WebPart properties during edition of SharePoint site. As you can imagine it could be quite big problem during work on SharePoint 2013.
On below screen you can see unusual appearance of webpart. In this scenario there is no access to webpart properties screen.
After long analysis of this problem I find out that is not SharePoint configuration problem. It is end user problem with configuration of Internet Explorer. Interesting thing is that it is necessary add SharePoint 2013 website to Compatibility Mode panel to work correctly.
To fix our problem open Internet Explorer, then Tools – Compatibility View settings.
In new window check Display intranet sites in Compatibility View option and add SharePoint site address to list by clicking on Add button.
After that our webpart will start to work in normal way.