The error:

“Internal Error: Failed to retrieve vim client”

occurs whenVCF Operations cannot establish a functional API session with vCenter. Thevim clientis the internal vSphere API client library used by VCF Operations to perform cluster actions such as modifying DRS settings, powering on/off workloads, or retrieving inventory.

When this error appears, VMware documentation identifies these common root causes:

Loss of connectivity between VCF Operations and vCenter

DNS resolution issues

Network interruption

Stale or expired authentication tokens

Credential mismatchIf the vCenter password was changed manually, VCF Operations may be unable to authenticate.

vCenter services restarting or unavailableIf vCenter backend services (vpxd, sts, etc.) are unstable, VCF Operations cannot establish a vim session.

Option A is incorrect—DRS automation state in the vSphere Client does not cause vim client retrieval errors.

Option B (vCenter overloaded by API requests) would cause timeouts, not a vim client initialization failure.

Option D (insufficient licensing) affects feature use, not API connectivity.