Remove
Important
LDAPCP Classic is deprecated. Migrating to LDAPCP SE is safe and easy.
Important
Always start a new PowerShell process to ensure using up to date persisted objects and avoid nasty errors.
Reset property ClaimProviderName in the SPTrustedIdentityTokenIssuer
Unfortunately, the only supported way to reset property ClaimProviderName is to remove and recreate the SPTrustedIdentityTokenIssuer object, which requires to remove the trust from all the web apps where it is used.
Alternatively, this property can be reset using .NET reflection, but this is not supported and you do this at your own risks:
Uninstall LDAPCP
Randomly, SharePoint doesn’t uninstall the solution correctly: it removes the assembly too early and fails to call the feature receiver… When this happens, the claims provider is not removed and that causes issues when you re-install it.
To uninstall safely, deactivate the farm feature before retracting the solution: