Recibo un error al intentar crear predicciones de aprendizaje profundo con h2o en R. El error se produce en aproximadamente un tercio de las predicciones con el comando h2o.predict. Aquí está la configuración del modelo:

localH2O = h2o.init(ip = "localhost", port = 54321, startH2O = TRUE,max_mem_size='20g',nthreads=6)
model <- h2o.deeplearning(x = 2:100, y = 1, training_frame = x, l1 = 1e-5, l2 = 1e-5, epochs=500, hidden = c(800,800,100))
prediction <- h2o.predict(model, x[,2:100])

Aquí está el error que ocurre dentro y fuera:

ERROR: Unexpected HTTP Status code: 500 Server Error (url = http://localhost:54321/99/Rapids)

java.lang.RuntimeException
[1] "water.MRTask.getResult(MRTask.java:505)"                             ,                 
[2] "water.MRTask.doAll(MRTask.java:379)"                                                  
[3] "water.MRTask.doAll(MRTask.java:375)"                                                  
[4] "water.rapids.ASTRowSlice.apply(ASTColSlice.java:123)"                                 
[5] "water.rapids.ASTExec.exec(ASTExec.java:46)"                                           
[6] "water.rapids.ASTTmpAssign.apply(ASTAssign.java:255)"                                  
[7] "water.rapids.ASTTmpAssign.apply(ASTAssign.java:248)"                                  
[8] "water.rapids.ASTExec.exec(ASTExec.java:46)"                                           
[9] "water.rapids.Session.exec(Session.java:56)"                                           
[10] "water.rapids.Exec.exec(Exec.java:63)"                                                 
[11] "water.api.RapidsHandler.exec(RapidsHandler.java:23)"                                  
[12] "sun.reflect.GeneratedMethodAccessor8.invoke(Unknown Source)"                          
[13] "sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)"
[14] "java.lang.reflect.Method.invoke(Method.java:497)"                                     
[15] "water.api.Handler.handle(Handler.java:64)"                                            
[16] "water.api.RequestServer.handle(RequestServer.java:644)"                               
[17] "water.api.RequestServer.serve(RequestServer.java:585)"                                
[18] "water.JettyHTTPD$H2oDefaultServlet.doGeneric(JettyHTTPD.java:617)"                    
[19] "water.JettyHTTPD$H2oDefaultServlet.doPost(JettyHTTPD.java:565)"                       
[20] "javax.servlet.http.HttpServlet.service(HttpServlet.java:755)"                         
[21] "javax.servlet.http.HttpServlet.service(HttpServlet.java:848)"                         
[22] "org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:684)"               

Show Traceback

Rerun with Debug
Error in .h2o.doSafeREST(h2oRestApiVersion = h2oRestApiVersion, urlSuffix = page,  : 
water.DException$DistributedException: from /127.0.0.1:54321; by class water.rapids.ASTRowSlice$1; class java.lang.NegativeArraySizeException: null Error in class(obj) <- "rs.scalar" : attempt to set an attribute on NULL

Aquí hay algo sobre la arquitectura de mi sistema. El sistema en ejecución ("java -version") proporciona:

java version "1.8.0_65"
Java(TM) SE Runtime Environment (build 1.8.0_65-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.65-b01, mixed mode)

Aquí está la salida de sessionInfo ():

R version 3.2.2 (2015-08-14)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows Server 2008 R2 x64 (build 7601) Service Pack 1

locale:
[1] LC_COLLATE=Danish_Denmark.1252  LC_CTYPE=Danish_Denmark.1252    LC_MONETARY=Danish_Denmark.1252
[4] LC_NUMERIC=C                    LC_TIME=Danish_Denmark.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] h2o_3.6.0.8              statmod_1.4.22           TTR_0.23-0               selectiveInference_1.1.1
[5] intervals_0.15.1         lars_1.2                 glmnet_2.0-2             foreach_1.4.3           
[9] Matrix_1.2-2             wq_0.4.4                 zoo_1.7-12               skm_1.0.2               
[13] stringi_1.0-1            devtools_1.9.1          

loaded via a namespace (and not attached):
[1] Rcpp_0.12.2      magrittr_1.5     MASS_7.3-43      munsell_0.4.2    colorspace_1.2-6
[6] lattice_0.20-33  stringr_1.0.0    plyr_1.8.3       xts_0.9-7        tools_3.2.2     
[11] grid_3.2.2       gtable_0.1.2     iterators_1.0.8  digest_0.6.8     reshape2_1.4.1  
[16] ggplot2_1.0.1    bitops_1.0-6     codetools_0.2-14 RCurl_1.95-4.7   memoise_0.2.1   
[21] scales_0.3.0     jsonlite_0.9.19  proto_0.3-10    

Cualquier ayuda muy apreciada.