I had disabled the FirstName field in the shield encrption
But in the Page I'm getting the error saying that
I found that The limitations and special behaviors that apply to encrypted fields persist after encryption is disabled. The values can remain encrypted at rest and masked in some places.. How can I overcome this Any ideas
If you only disable encryption, this is not enough to have the features, such as filtering or aggregation back, because you still might have ciphertexts in the corresponding column.
Please contact the support team, and they will run a job on your behalf to mass decrypt your data, and then your field will have all the features back.
From the exception you've got there, it looks like your Visualforce page has been impacted by previous encryption you've made. Although you've disabled the encryption on Contact.Name/Account.Name - which is a composite field, i.e., comprised of FirstName and LastName - the underlying encrypted values are not reverted back to plain text automatically.
In this case, try to open the record via vanilla page layout (if possible) and update a particular record or retrieve the Id, First Name, and Last Name via Data Loader so you'd retrieve them in plain text, then mass-update them again via Data Loader so this time they'd be persisted in plain text. Then your VFP should work again.
Alternative solution is to keep the Contact.Name / Account.Name encrypted but update your SOQL such that it complies with the restrictions by using formula/functions that are supported by Shield. Check out the latest version of Shield's implementation guide
