Unable to extract key information from \"/config/filestore/files_d/partition_d/ to /var/system/tmp/t

Have you tried using the DELETE method on the existing CSR, rather than deleting it using tmsh?  The iControlREST API for /tm/sys/crypto/csr appears to support that method.

oh! yes I understood the process.

to Renew the csr and keep the same key and cert,  delete the csr and create a new one :

1) delete the old CSR:

csr1 = mgmt.tm.sys.file.ssl_csrs.ssl_csr.load(name=csr_found['name'], partition=partition_name)
csr1.delete()

2) create a new one,  by specifying the key location

csr = mgmt.tm.util.bash.exec_cmd('run',
utilCmdArgs=f"-c 'tmsh create sys crypto csr /{name[1]}/{name[2]} "
f"admin-email-address \"{email}\" "
f"city \"{cert_found['city']}\" "
f"common-name \"{name[2]}\" "
f"country \"{cert_found['country']}\" "
f"email-address \"{email}\" "
f"key \"{key_found['name']}\" "
f"organization \"{cert_found['organization']}\" "
f"state \"{cert_found['state']}\" "
f"subject-alternative-name \"{cert_found['subjectAlternativeName']}\" "
f"'")

Thank you VernonWells