Cannot save Code Style settings due to "FileAlreadyExistsException: xxx\...\codeStyles"

Problem

When modifying Code Style settings, it fails to get saved.

By checking the logs, we can see such an exception:

java.nio.file.FileAlreadyExistsException: xxx\...\codeStyles
at java.base/sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:87)
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:103)
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:108)
at java.base/sun.nio.fs.WindowsFileSystemProvider.createDirectory(WindowsFileSystemProvider.java:527)
at java.base/java.nio.file.Files.createDirectory(Files.java:699)
at com.intellij.openapi.util.io.NioFiles.tryCreateDirectory(NioFiles.java:96)
at com.intellij.openapi.util.io.NioFiles.createDirectories(NioFiles.java:78)
at com.intellij.configurationStore.DirectoryBasedStorage$DirectorySaveSessionProducer.saveStates(DirectoryBasedStorage.kt:297)
at com.intellij.configurationStore.DirectoryBasedStorage$DirectorySaveSessionProducer.doSave(DirectoryBasedStorage.kt:259)
at com.intellij.configurationStore.DirectoryBasedStorage$DirectorySaveSessionProducer.access$doSave(DirectoryBasedStorage.kt:172)
at com.intellij.configurationStore.DirectoryBasedStorage$DirectorySaveSessionProducer$save$2.invoke(DirectoryBasedStorage.kt:247)
at com.intellij.configurationStore.DirectoryBasedStorage$DirectorySaveSessionProducer$save$2.invoke(DirectoryBasedStorage.kt:247)
at com.intellij.openapi.progress.CoroutinesKt.blockingContextInner(coroutines.kt:339)
at com.intellij.openapi.progress.CoroutinesKt$blockingContext$2.invokeSuspend(coroutines.kt:232)
at com.intellij.openapi.progress.CoroutinesKt$blockingContext$2.invoke(coroutines.kt)
at com.intellij.openapi.progress.CoroutinesKt$blockingContext$2.invoke(coroutines.kt)
at kotlinx.coroutines.intrinsics.UndispatchedKt.startUndispatchedOrReturn(Undispatched.kt:62)
at kotlinx.coroutines.CoroutineScopeKt.coroutineScope(CoroutineScope.kt:261)
at com.intellij.openapi.progress.CoroutinesKt.blockingContext(coroutines.kt:231)
at com.intellij.configurationStore.DirectoryBasedStorage$DirectorySaveSessionProducer.save(DirectoryBasedStorage.kt:247)
at com.intellij.configurationStore.SaveSessionProducerManager.saveSessions(SaveSessionProducerManager.kt:70)
at com.intellij.configurationStore.ProjectSaveSessionProducerManager.saveAndValidate(ProjectSaveSessionProducerManager.kt:15)
at com.intellij.configurationStore.ProjectStoreImpl$doSave$2$1.invokeSuspend(ProjectStoreImpl.kt:376)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104)
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:608)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:873)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:763)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:750)

Resolution

Please check if there is a component called "ProjectCodeStyleConfiguration" in ${idea.config.path}/options/project.default.xml or not.

If the component exists, please remove it, and remove the codeStyles file in your Project directory. Then restart the IDE.