Cryptomator corrupted my files

After doing a test encryption of about 20GB , only a few files seem to be readable while the rest seems to be junk such as having original size but not usable . I try to cut and paste back to desktop but was unable to do so due to some admin issue.

Hope expert can address this

Which OS? Which interface (dokany or WebDAV)?
Is there a detailed error message?

Win 10 , No error just file cannot be read according to windows error.
That is after decrypting it

Are these files by chance write-protected?

No , I have been using cryptomator for quite some time already . Been fine with small files , however when it comes to big files like transferring huge amount of data, this happened. They are video files by the way

I’m also experiencing the same issue leading to corrupted files (images) and Windows returning copy / permission errors. If I take a look at the cryptomator log file, I can see the actual cause:

03:17:28.386 [Thread-209476] TRACE o.c.frontend.dokany.ReadWriteAdapter - zwCreateFile() is called for /somedir/somefile.JPG with CreationDisposition OPEN_EXISTING.
03:17:28.387 [Thread-209476] TRACE o.c.frontend.dokany.ReadWriteAdapter - Try to open /somedir/somefile.JPG as File.
03:17:28.387 [Thread-209476] TRACE o.c.cryptofs.fh.FileHeaderHolder - Reading file header from D:\crytomatordir\d\SB\26UFDWITBR36YK2YDB6LEQVE4L37SP\YUBNL3VPD3FLMTCYDN4UT4MVL5EX6ENP5P3R5VMRQ7CQXQYTOVXWRTJ6CN36K===
03:17:28.388 [Thread-209476] DEBUG o.c.frontend.dokany.ReadWriteAdapter - zwCreateFile(): IO error occurred during opening handle to /somedir/somefile.JPG.
03:17:28.388 [Thread-209476] DEBUG o.c.frontend.dokany.ReadWriteAdapter - zwCreateFile(): Unable to decrypt header of file D:\crytomatordir\d\SB\26UFDWITBR36YK2YDB6LEQVE4L37SP\YUBNL3VPD3FLMTCYDN4UT4MVL5EX6ENP5P3R5VMRQ7CQXQYTOVXWRTJ6CN36K===
at org.cryptomator.cryptofs.fh.FileHeaderHolder.loadExisting(
at org.cryptomator.cryptofs.fh.OpenCryptoFile.newFileChannel(
at org.cryptomator.cryptofs.CryptoFileSystemImpl.newFileChannel(
at org.cryptomator.cryptofs.CryptoFileSystemImpl.newFileChannel(
at org.cryptomator.cryptofs.CryptoFileSystemProvider.newFileChannel(
at java.base/
at org.cryptomator.frontend.dokany.OpenHandleFactory.openFile(
at org.cryptomator.frontend.dokany.ReadWriteAdapter.createFile(
at org.cryptomator.frontend.dokany.ReadWriteAdapter.zwCreateFile(
at jdk.internal.reflect.GeneratedMethodAccessor11.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(
at java.base/java.lang.reflect.Method.invoke(
at com.sun.jna.CallbackReference$DefaultCallbackProxy.invokeCallback(
at com.sun.jna.CallbackReference$DefaultCallbackProxy.callback(
Caused by: org.cryptomator.cryptolib.api.AuthenticationFailedException: Header MAC doesn’t match.
at org.cryptomator.cryptolib.v1.FileHeaderCryptorImpl.decryptHeader(
at org.cryptomator.cryptofs.fh.FileHeaderHolder.loadExisting(
… 15 common frames omitted

It seems related to the header.

I am experiencing the same issue! Interestingly enough Cyberduck can decrypt the affected files without any problem.

EDIT: Just tried using the iPhone App - and it opens the affected files just fine. Only Cryptomator on Windows fails.