I’ve been using Crypt::LE for about years to acquire certs from Lets Encrypt. It is the core of a C# app (partially) automating cert acquisition.
My domain is: lacerate.com lacearte.com
I ran this command:
le64.exe --key lacearte_com_Acct.key --csr lacearte_com.csr --csr-key lacearte_com.key --crt lacearte_com.crt --domains "lacearte.com,mail.lacearte.com,www.lacearte.com" --generate-missing --handle-as HTTP --live --delayed
<>
le64.exe --key lacearte_com_Acct.key --csr lacearte_com.csr --csr-key lacearte_com.key --crt lacearte_com.crt --domains "lacearte.com,mail.lacearte.com,www.lacearte.com" --generate-missing --handle-as HTTP --live
It produced this output:
2026/05/10 17:03:22 [ Crypt::LE client v0.39 started. ]
2026/05/10 17:03:22 Loading an account key from lacearte_com_Acct.key
2026/05/10 17:03:22 Loading a CSR from lacearte_com.csr
2026/05/10 17:03:23 Registering the account key
2026/05/10 17:03:24 The key is already registered. ID: 2398714517
2026/05/10 17:03:25 Challenge for lacearte.com requires:
A file 'QqIMBx27sgdwQNKQbqawwxMf5YxGFwBQYcMaF3FfqPI' in '/.well-known/acme-challenge/' with the text: QqIMBx27sgdwQNKQbqawwxMf5YxGFwBQYcMaF3FfqPI.rNtcLQ4ID4dyuBOWrgDcEdci9BzETG3UIubwamt4610
2026/05/10 17:03:25 Challenge for mail.lacearte.com requires:
A file 's6T8vLDg6BFVXU5P5YQkb3nkYjYd4IZ48tTY439HonI' in '/.well-known/acme-challenge/' with the text: s6T8vLDg6BFVXU5P5YQkb3nkYjYd4IZ48tTY439HonI.rNtcLQ4ID4dyuBOWrgDcEdci9BzETG3UIubwamt4610
2026/05/10 17:03:25 Challenge for www.lacearte.com requires:
A file 'qFUHa1zi929ymkKuqLMRN2Tg_eO8SZUNSFF3aVxaTB8' in '/.well-known/acme-challenge/' with the text: qFUHa1zi929ymkKuqLMRN2Tg_eO8SZUNSFF3aVxaTB8.rNtcLQ4ID4dyuBOWrgDcEdci9BzETG3UIubwamt4610
D:__TMP_getcert\CertWorking>
After required challenge responses are upload process continuation occurs by running the initial command without the delayed flag. Historically the required challenge responses are the same for both runs but as depicted below that has changed. The Crypt::LE client has not changed since mid 2023.
2026/05/10 17:07:36 [ Crypt::LE client v0.39 started. ]
2026/05/10 17:07:36 Loading an account key from lacearte_com_Acct.key
2026/05/10 17:07:36 Loading a CSR from lacearte_com.csr
2026/05/10 17:07:37 Registering the account key
2026/05/10 17:07:38 The key is already registered. ID: 2398714517
2026/05/10 17:07:39 Challenge for lacearte.com requires:
A file 'RT6yJ8YXC2qEERAPNTU76yxe-eHEX47R__ZST_F7MR4' in '/.well-known/acme-challenge/' with the text: RT6yJ8YXC2qEERAPNTU76yxe-eHEX47R__ZST_F7MR4.rNtcLQ4ID4dyuBOWrgDcEdci9BzETG3UIubwamt4610
When done, press
2026/05/10 17:09:23 Challenge for mail.lacearte.com requires:
A file 'kSGE_JlsTclGYKh9xPZQXIDIKRqL0f6_lkgHZrezOe0' in '/.well-known/acme-challenge/' with the text: kSGE_JlsTclGYKh9xPZQXIDIKRqL0f6_lkgHZrezOe0.rNtcLQ4ID4dyuBOWrgDcEdci9BzETG3UIubwamt4610
When done, press
2026/05/10 17:11:05 Challenge for www.lacearte.com requires:
A file 'ir-1KaAaBO0CAM6vK0EniBie1O0bL9Ko7W99HY9p2lo' in '/.well-known/acme-challenge/' with the text: ir-1KaAaBO0CAM6vK0EniBie1O0bL9Ko7W99HY9p2lo.rNtcLQ4ID4dyuBOWrgDcEdci9BzETG3UIubwamt4610
When done, press
2026/05/10 17:14:56 Domain verification results for 'lacearte.com': success.
2026/05/10 17:14:56 You can now delete the 'RT6yJ8YXC2qEERAPNTU76yxe-eHEX47R__ZST_F7MR4' file.
2026/05/10 17:14:59 Domain verification results for 'mail.lacearte.com': success.
2026/05/10 17:14:59 You can now delete the 'kSGE_JlsTclGYKh9xPZQXIDIKRqL0f6_lkgHZrezOe0' file.
2026/05/10 17:15:02 Domain verification results for 'www.lacearte.com': success.
2026/05/10 17:15:02 You can now delete the 'ir-1KaAaBO0CAM6vK0EniBie1O0bL9Ko7W99HY9p2lo' file.
2026/05/10 17:15:02 Requesting domain certificate.
2026/05/10 17:15:02 Requesting issuer's certificate.
2026/05/10 17:15:02 Saving the full certificate chain to lacearte_com.crt.
2026/05/10 17:15:02 The job is done, enjoy your certificate!
Checking the API Announcements there is nothing mentioned that could affect this functionality. Has some “unannounced” tweak occurred which was expected to be transparent to end users that could be causing this? Nothing has changed in my arena…