This is a common question, I understand you are having trouble with the DoubleClick components in the component inspector. Here is my recommendation:
1) The first option is to restart your computer. This will typically fix the issue.
2) Please make sure you are using the correct components version on AS2 or AS3 with the same ActionScript version of your file.
3) If the problem persists, you can solve the problem by editing your mm.cfg file, as follows:
1) Exit Flash. 2) Find the mm.cfg file on your computer. For instructions on how to do this, see Editing the mm.cfg file in the Adobe Flex help center. 3) Open the file in a text editor. 4) Change the contents as to: