Loading the form/list with the encrypted text field throws below error,

Fields encrypted with 'XXXXXX' encryption context are unavailable

Looking into the node log revealed below exception,

2018-11-13 05:31:12 (286) Default-thread-8 2778DAB0DB356F004FFAF1061D9619EF txid=52495eb0db35 SEVERE *** ERROR *** Input length must be multiple of 16 when decrypting with padded cipher
javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
 at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:936)
 at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:847)
 at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:446)
 at javax.crypto.Cipher.doFinal(Cipher.java:2164)
 at com.glide.encryption.PlatformEncrypterDecrypter.getDecryptedValue(PlatformEncrypterDecrypter.java:86)
 ...
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 at java.lang.Thread.run(Thread.java:748)

• The error message occurs when the encrypted field is set with value null (Technical Support can verify this in the database).
• Possibly the encrypted field was set to null by a scheduled cleanup job or any other processes.

Review the custom clean up scripts / Scheduled job and modify it accordingly so that it doesn't set the encrypted fields to null after clone/upgrade.

Encryption support