DeepSea v4 often uses a technique that prevents decompilers from mapping the assembly correctly. If your decompiler throws an error upon loading the file, you are likely hitting a metadata "trap."
Testing your own obfuscation settings to see how easily they can be bypassed. deepsea obfuscator v4 unpack
Once the application is in memory and the strings are decrypted, use a tool like MegaDumper to grab the clean MSIL from the process memory. Phase 4: Reconstructing Control Flow DeepSea v4 often uses a technique that prevents