Unable to install/renew certificate on zimbra 8.8.15

i have followed this topic:

but heving issue with command:
/opt/zimbra/bin/zmcertmgr deploycrt comm cert.pem LE.CA.pem

The output error is:
[zimbra@mail letsencrypt] /opt/zimbra/bin/zmcertmgr deploycrt comm cert.pem LE.CA.pem ** Verifying 'cert.pem' against '/opt/zimbra/ssl/zimbra/commercial/commercial.key' Certificate 'cert.pem' and private key '/opt/zimbra/ssl/zimbra/commercial/commercial.key' match. ** Verifying 'cert.pem' against 'LE.CA.pem' ERROR: Unable to validate certificate chain: Error loading file LE.CA.pem 140127807342248:error:0D07207B:asn1 encoding routines:ASN1_get_object:header too long:asn1_lib.c:157: 140127807342248:error:0D068066:asn1 encoding routines:ASN1_CHECK_TLEN:bad object header:tasn_dec.c:1188: 140127807342248:error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error:tasn_dec.c:374:Type=X509 140127807342248:error:0907400D:PEM routines:PEM_X509_INFO_read_bio:ASN1 lib:pem_info.c:249: 140127807342248:error:0B084009:x509 certificate routines:X509_load_cert_crl_file:PEM lib:by_file.c:259: [zimbra@mail letsencrypt]

Did you create file?

The file doesn’t exist.
You will need to create it using the information provided in that post.

Yes we have created and the file looks like the one provided in previous post.