Solution error:/GEN already exists but is not a source folder. convert to a source folder or rename it

Today, the project path in the workspace is changed, and this error occurs. This error is generally caused by changes to the function library or path resetting.
/Myproject/GEN already exists but is not a source folder. convert to a source folder or rename it.

The solution to this error is as follows:

1. Right-click myproject under package worker Eer and select Properties.

2. Select Java build path and then source.

3. Click Add folder on the right, select the gen folder, click OK, and then yes.

4. Click OK on the main panel of properties.

5. Right-click myproject under package named eer, select Android tools, and click fix project properties.

In this way, the gen folder is converted into a source folder.

Now we can go to project-> clean to find that the error no longer appears.

It is worth noting that if this error is caused by path resetting, the SRC folder must be converted into a real source folder (a box-shaped package sign appears) according to the above method ).