iOS Question Communication Error: ConnectFailure


Licensed User

I am wanting try out B4i, and from what I could read in the forums you do not need the Apple Developer account if you can use Apple Simulator.
I have installed the Local Mac Builder along with the latest XCode (and ran it), I can ping my Mac but I cannot get the compiler to connect to my Mac:

B4i Version: 8.10
Parsing code.    (0.00s)
Building folders structure.    (0.02s)
Compiling code.    (0.00s)
Compiling layouts code.    (0.00s)
Building Xcode project.    (0.10s)
icon-store-1024.png is missing from Files\Special. Using default icon.
Preparing project for builder.    (0.02s)
    Project size: 0.15 MB
Sending data to remote compiler.    Error
Communication error: ConnectFailure

I have tried turning of my firewall completely, disabled stealth mode, disabled private iCloud traffic, disabled Little Snitch, forced open the 51042 port via config file and turned about every stone I could think of...
Any suggestion on what to do?
Last edited:


Licensed User
Server output:
Build server version: 8.10
2023-01-23 17:28:57.199:INFO::main: Logging initialized @340ms to org.eclipse.jetty.util.log.StdErrLog
Loading default configuration file.
Mac version: 10.16
Xcode path: /Applications/
Xcode version: 14.2
2023-01-23 17:28:57.913:INFO:oejs.Server:main: jetty-9.4.z-SNAPSHOT; built: 2018-05-03T15:56:21.710Z; git: daa59876e6f384329b122929e70a80934569428c; jvm 14.0.1+7
2023-01-23 17:28:57.966:INFO:oejs.session:main: DefaultSessionIdManager workerName=node0
2023-01-23 17:28:57.967:INFO:oejs.session:main: No SessionScavenger set, using defaults
2023-01-23 17:28:57.970:INFO:oejs.session:main: node0 Scavenging every 660000ms
2023-01-23 17:28:57.978:INFO:oejsh.ContextHandler:main: Started o.e.j.s.ServletContextHandler@6dde5c8c{/,file:///Users/<myUser>/www,AVAILABLE}
2023-01-23 17:28:57.980:INFO:oejs.AbstractNCSARequestLog:main: Opened /Users/<myUser>/logs/b4j-2023_01_23.request.log
2023-01-23 17:28:58.015:INFO:oejs.AbstractConnector:main: Started ServerConnector@2c2efe59{HTTP/1.1,[http/1.1]}{}
2023-01-23 17:28:58.397:INFO:oejus.SslContextFactory:main: x509=X509@65d6b83b(jetty,h=[],w=[]) for SslContextFactory@d706f19[provider=null,keyStore=file:///Users/<myUser>/key/key.jks,trustStore=null]
2023-01-23 17:28:58.398:INFO:oejus.SslContextFactory:main: x509=X509@30b7c004(rootca,h=[],w=[]) for SslContextFactory@d706f19[provider=null,keyStore=file:///Users/<myUser>/key/key.jks,trustStore=null]
2023-01-23 17:28:58.597:INFO:oejs.AbstractConnector:main: Started ServerConnector@6069db50{SSL,[ssl, http/1.1]}{}
2023-01-23 17:28:58.600:INFO:oejs.Server:main: Started @1745ms
Build server is ready
Build server version: 8.10

Local output:
B4i Build Server

Build server is running.
Version: 8.1
Server time: 18:41:00
Mac SSL Key

Key IP:
SSL port: 51042
h files

a files

PC cannot open the URL
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Licensed User
To investigate further I installed php on my Mac and ran
php -S in a folder with a simple php.index file (sets up a simple webserver).

My Windows PC got access to this right away, so there should not be a problem with the Mac receiving incomming traffic.
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Licensed User
I am not a network expert, but as both a webserver and also SMB folders is accessible from the Windows PC, I do not see how it could be the router?!

Is there any parameters I can pass the builder in order to change the ports?
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B4X founder
Staff member
Licensed User
Longtime User
You cannot change the port.

I am not a network expert, but as both a webserver and also SMB folders is accessible from the Windows PC, I do not see how it could be the router?!
Test it in a different network. You can use a phone as a hotspot and connect the PC and Mac to this network.
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