要解决“崩溃的Retrofit + RxJava + SSL证书”问题，可以按照以下步骤进行操作：

1. 导入所需的库：

在项目的build.gradle文件中，添加以下依赖项：

implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
implementation 'com.squareup.retrofit2:adapter-rxjava2:2.9.0'
implementation 'io.reactivex.rxjava2:rxjava:2.2.21'
implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'

2. 创建SSL证书：

首先，将SSL证书文件（.crt或.pem格式）放入项目的res/raw目录下。

3. 创建网络请求接口：

public interface ApiService {
    @GET("your_api_endpoint")
    Observable yourApiMethod();
}

4. 创建Retrofit实例：

public class RetrofitClient {
    private static final String BASE_URL = "https://your.base.url/";
    private static Retrofit retrofit;

    public static Retrofit getRetrofitInstance(Context context) {
        if (retrofit == null) {
            try {
                // 加载SSL证书
                CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
                InputStream inputStream = context.getResources().openRawResource(R.raw.your_certificate);
                Certificate certificate = certificateFactory.generateCertificate(inputStream);
                inputStream.close();

                // 创建KeyStore并将证书导入
                KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
                keyStore.load(null, null);
                keyStore.setCertificateEntry("your_certificate_alias", certificate);

                // 创建TrustManagerFactory并初始化KeyStore
                TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
                trustManagerFactory.init(keyStore);

                // 创建SSLContext并使用TrustManagerFactory初始化
                SSLContext sslContext = SSLContext.getInstance("TLS");
                sslContext.init(null, trustManagerFactory.getTrustManagers(), null);

                // 创建OkHttpClient并设置SSL SocketFactory
                OkHttpClient okHttpClient = new OkHttpClient.Builder()
                        .sslSocketFactory(sslContext.getSocketFactory(), (X509TrustManager)trustManagerFactory.getTrustManagers()[0])
                        .build();

                // 创建Retrofit实例
                retrofit = new Retrofit.Builder()
                        .baseUrl(BASE_URL)
                        .client(okHttpClient)
                        .addConverterFactory(GsonConverterFactory.create())
                        .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                        .build();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return retrofit;
    }
}

5. 发起网络请求：

ApiService apiService = RetrofitClient.getRetrofitInstance(context).create(ApiService.class);

apiService.yourApiMethod()
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(new Observer() {
            @Override
            public void onSubscribe(Disposable d) {
                // 订阅成功
            }

            @Override
            public void onNext(YourResponseModel yourResponseModel) {
                // 请求成功
            }

            @Override
            public void onError(Throwable e) {
                // 请求失败
            }

            @Override
            public void onComplete() {
                // 请求完成
            }
        });

请注意，上述代码中的your.api.endpoint和your_certificate需要根据实际情况进行替换。

这样，您就可以使用Retrofit + RxJava + SSL证书进行安全的网络请求了。