(ChkDsk) Recover orphaned .c9r files from Cryptomator vault

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1

I experienced a failure while writing data to an external hard drive, which caused an abrupt disconnection and the loss of a folder inside a Cryptomator vault. After running chkdsk, it couldn’t restore the missing folder, but it did find some orphaned files and placed them in found.000 at the root of the external drive.

E:\: My external HD.
F:\: My mounted vault.

Inside E:\found.000, there are several directories and .c9r files that partially resemble the encrypted vault structure. For example:

E:\found.000\
|
|   00000000-dir.c9r
|   
+---10000000-FWUAZBR4KS4P4VTYEBQRKE7N6DUGY2
|       dirid.c9r
|       
+---dir0000.chk
|   +---24U6THHZ6PZXMIUDHFDP53ZNKAJJLM
|   +---4AEUQZVOB3P55ZVUCZ2VHKEV3PPCCC
|   |       Vmhra2eq-FzSIMhUL0QHopNwJAD2emEeJfpxTQ==.c9r
|   |       
|   +---H5BWHF54F4PGBPL34NJ6FU3H3ABDEM
|   |       VTnNgZp0FH7T-5T-DcdTySEb52erosXbZb8sSdNAVwLer5rux3sPkgdD9A==.c9r
|   |       w4z-43gPaX907pw_fN3B6d3wU6RfRGJB_fNaQXaq7kAe6ZDxSZE35jBC.c9r
|   |       yP0_1225ZYvsRQYJEeKviXibUCEFz-izwvv4Ci8pQnvt85ZUOQ==.c9r
|   |       
|   +---I5C4B7Q4TARAB5OENOTPOF3KU6JYQQ
|   |       -2QlGDDKcMfFhYcSPfSwc37rQCX8WBR2G4gubpvbNalaUMYQ0a0cgHIN6sTtBp-GzRsa8Ijjc6eC_w==.c9r
|   |       -k8Wb7AUObsXuQO72-WDzMyFQqkxWRqZv5OIyT5MGsWJDN6GtiH64K4lGsUH6E_g-ccTWT3R5g4miw==.c9r
|   |       
|   \---OKP3HQPYIGLZTPXDV7YZL2E76KSL6L
|           0myneMBcP1PBJyd3vw577LRc0RuUpm5IFQs8LUdy5LP2zozOGiApzXnYKz2cfq8=.c9r
|           2Q7zY5xfKYr7nyyCR4OLClZb75gGivABba8=.c9r
|           5Cyn3oRTWLMSqcMFp8LrfeOhwE4POSzlN9gJfSYDC6MUFZZSQj9GHIAIxQ==.c9r
|           dirid.c9r
|           
+---dir0001.chk
|       AglH33iVQFwZHH389Mjdnt6innN5qFySXl_nLyB6DaZDJoIo85nmEkYYU0RqSp75GMvUWCkMLA==.c9r
|       J3_5VoMUrX69UkoCvsxo1mTUA0M0J7Ki9LC4SFZ_dIpsQRxfx89UWzos_x-1BodXh9OPVD7kkQ==.c9r
|       tV0loEexTOBBtdgHBHAgCx3MuWPCkWJk0ugNbrLYJSap8H2y8YGYbilO1n2F0qZzgpbXKKq84w==.c9r
|       
\---dir0002.chk
    |   6BvIWYqGA18M1-kUchBiSqQV8-VBinwUAUOwAuDonZDrMY0QBKOyIBWyararNBMCRhGpHSQmg0E6m6Z9snU5YSQUB3C4H2n9dVgdBUvqrUji784V4AMd3u26spYlos2rAjdlSqM9qd5Ig2WC.c9r
    |   9Ops5lrv7omcp8XJAg2vvBbYxreFtP5bYr7g7LotfxLZehJ6oBMvbXlfpogfiVvqjkMGa0IydfKhaxOJxuhRXD02spNM7N3AtagfaLRFLOpFg3k-uzmEpz2fLjlFnPSeimtVtwnbhiU6UE8=.c9r
    |   BeiwUWYN5AXGySpINXHDYsNMByt4ALzoi6F-5CHvP0PADFRL0kv1sTpi7BUvLIKQK_ZVyWM-PkscdYMJEYCmRNPPyIdPpa5Z-F3i2-ngwzBixbWMTJW-qeR9qg7RIjHOi3UTNMCpiClmD5I8.c9r
    |   dirid.c9r
    |   
    +---1AMASAxRzdG27UTAv1Or-YqLZqLjAAFf8Gvjz-YTcs2eKM0dj4X0XpqqaZQxew==.c9r
    |       dir.c9r
    |       
    \---_-lt3X25TsXX6ueHQkeQQGKBaE2_14FoQw==.c9r
            dir.c9r

What I tried:

  1. I created a new file inside the mounted vault: F:\temp\myfile.txt.
  2. I located the encrypted version of that file:
    E:\myVault\d\KD\SUY345B4VJVL3BMGKOAPHUHOI2UPFE\vQNELBiw1sUdYhE-JQ4lGbUZDJfSz1A=.c9r.
  3. I then inserted some .c9r files recovered from E:\found.000 into that exact folder:
    E:\myVault\d\KD\SUY345B4VJVL3BMGKOAPHUHOI2UPFE\.
  4. But when I opened the vault, nothing else appears in F:\temp\.
    Not even after performing the vault health check (Sanitizer).

WHY?

Is there any way to recover these .c9r files?

2

The integrity check is flawed and fails to recognize orphaned .c9r files. I wonder how many .c9r files are lost in limbo in my vault, unrecognized as files when the vault is mounted.