**Axon.ivy 7.1 and later**
This should be no problem anymore. All source folders are now optional in `.classpath`. If you have an older project, there is project migration which makes all source folders optional.
**Axon.ivy 7.0 and prior**
You can modify the file `.classpath` in the root folder of your project manually. Modify all `classpathentry` of `kind`=`src`.
*Before*
<classpathentry <classpathentry kind="src" path="src"/>
*After*
<classpathentry <classpathentry kind="src" path="src">
<attributes><attributes>
<attribute <attribute name="optional" value="true"/>
</attributes></attributes>
</classpathentry></classpathentry>
