after checking out a java maven project, my pom has some errors all the time. maven clean and maven install work like a charm, but maven update project or download sources/java doc give me everytime the following error:

```
Could not download sources or javadoc
Could not read maven project
Some problems were encountered while processing the POMs:
[ERROR] Non-resolvable import POM: Failure to transfer io.github.jhipster:jhipster-dependencies:pom:3.0.1 from https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced. Original error: Could not transfer artifact io.github.jhipster:jhipster-dependencies:pom:3.0.1 from/to central (https://repo.maven.apache.org/maven2): connect timed out @ line 106, column 16
[ERROR] 'dependencies.dependency.version' for io.github.jhipster:jhipster-framework:jar is missing. @ line 118, column 15
[ERROR] 'dependencies.dependency.version' for org.springframework.boot:spring-boot-starter-cache:jar is missing. @ line 123, column 15
[ERROR] 'dependencies.dependency.version' for com.fasterxml.jackson.datatype:jackson-datatype-hibernate5:jar is missing. @ line 127, column 15
[ERROR] 'dependencies.dependency.version' for com.fasterxml.jackson.datatype:jackson-datatype-hppc:jar is missing. @ line 131, column 15
[ERROR] 'dependencies.dependency.version' for com.fasterxml.jackson.datatype:jackson-datatype-jsr310:jar is missing. @ line 135, column 15
[ERROR] 'dependencies.dependency.version' for com.fasterxml.jackson.module:jackson-module-afterburner:jar is missing. @ line 139, column 15
[ERROR] 'dependencies.dependency.version' for com.h2database:h2:jar is missing. @ line 867, column 17
[ERROR] 'dependencies.dependency.version' for com.jayway.jsonpath:json-path:jar is missing. @ line 148, column 15
[ERROR] 'dependencies.dependency.version' for io.springfox:springfox-swagger2:jar is missing. @ line 154, column 15

```

Im behind a corporate proxy, which i already configured in eclipse. 

I had never anything to do with maven in my past, only checking worked for me every time.
The project is set up with jHipster.

Hope somebody can help me.

Thanks in advance.