Hi,
I’m a languagetool premium customer and switched it on with the API URL https://api.languagetoolplus.com/v2
I’m using office 26.2.4.2 (X86_64, Linux 7.0, de-DE)
Some time after Writer is open the following message appears
Saying:
The network connection to https://api.languagetoolplus.com/v2//check could not be established.
Error of the client:
(22) HTTP response code said error
My internet is working.
- Host api.languagetoolplus.com:443 was resolved.
- IPv6: 2a01:4f8:c17:b735::1, 2a01:4f8:c0c:31a5::1, 2a01:4f8:c012:e655::1, 2a01:4f8:c010:ae24::1
- IPv4: 138.201.94.34, 5.75.231.96, 91.107.141.152, 188.34.199.114
- Trying [2a01:4f8:c17:b735::1]:443…
- Connected to api.languagetoolplus.com (2a01:4f8:c17:b735::1) port 443
- ALPN: curl offers h2,http/1.1
- TLSv1.3 (OUT), TLS handshake, Client hello (1):
- CAfile: /etc/ssl/certs/ca-certificates.crt
- CApath: /etc/ssl/certs
- TLSv1.3 (IN), TLS handshake, Server hello (2):
- TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
- TLSv1.3 (IN), TLS handshake, Certificate (11):
- TLSv1.3 (IN), TLS handshake, CERT verify (15):
- TLSv1.3 (IN), TLS handshake, Finished (20):
- TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
- TLSv1.3 (OUT), TLS handshake, Finished (20):
- SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384 / X25519 / RSASSA-PSS
- ALPN: server accepted h2
- Server certificate:
- subject: CN=api.languagetoolplus.com
- start date: Jun 28 13:23:52 2026 GMT
- expire date: Sep 26 13:23:51 2026 GMT
- subjectAltName: host “api.languagetoolplus.com” matched cert’s “api.languagetoolplus.com”
- issuer: C=US; O=Let’s Encrypt; CN=YR1
- SSL certificate verify ok.
- Certificate level 0: Public key type RSA (2048/112 Bits/secBits), signed using sha256WithRSAEncryption
- Certificate level 1: Public key type RSA (2048/112 Bits/secBits), signed using sha256WithRSAEncryption
- Certificate level 2: Public key type RSA (4096/152 Bits/secBits), signed using sha256WithRSAEncryption
- Certificate level 3: Public key type RSA (4096/152 Bits/secBits), signed using sha256WithRSAEncryption
- using HTTP/2
- [HTTP/2] [1] OPENED stream for https://api.languagetoolplus.com/v2
- [HTTP/2] [1] [:method: HEAD]
- [HTTP/2] [1] [:scheme: https]
- [HTTP/2] [1] [:authority: api.languagetoolplus.com]
- [HTTP/2] [1] [:path: /v2]
- [HTTP/2] [1] [user-agent: curl/8.5.0]
- [HTTP/2] [1] [accept: /]
HEAD /v2 HTTP/2
Host: api.languagetoolplus.com
User-Agent: curl/8.5.0
Accept: /
- TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
- TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
- old SSL session ID is stale, removing
< HTTP/2 400
HTTP/2 400
< date: Fri, 04 Sep 2026 16:16:32 GMT
date: Fri, 04 Sep 2026 16:16:32 GMT
< access-control-allow-origin: *
access-control-allow-origin: *
< x-envoy-upstream-service-time: 24
x-envoy-upstream-service-time: 24
< server: istio-envoy
server: istio-envoy
< x-backend-server: k8s_gcp_66
x-backend-server: k8s_gcp_66
< x-request-id: 88DA:2A0104F80C17B7350000000000000001:01BB:6A9AEEE0:2FA5BA84:118507
x-request-id: 88DA:2A0104F80C17B7350000000000000001:01BB:6A9AEEE0:2FA5BA84:118507
< strict-transport-security: max-age=63072000
strict-transport-security: max-age=63072000<
- Connection #0 to host api.languagetoolplus.com left intact
I contacted the Languagetool-Team, but they said it’s a Libreoffice problem.
Thank you for reaching out.
The LibreOffice integration was developed by members of our open-source community, as well as LibreOffice itself. As we only provide the API key for accessing Premium features, we do not have direct control over the integration.
For this reason, we are unfortunately unable to assist with any technical issues you may encounter while using the LibreOffice integration.
I’m glad about any help