RubyGems repository - error fetching gem from internal gem server

I can't install gem locally that is stored in internal gem server

I followed the instructions in chapter 18 in the "Repository Management with Nexus" manual: http://books.sonatype.com/nexus-book/2.11/pdf/nxbook-pdf.pdf

I am using nexus-2.11.2-03

I can install gems that are found on RubyGems.org but I can't install gems that are in my internal gem server. I am able to install the nexus gem and push my internal gem to the internal gem repository. Everything documented in chapter 18 works for me except for the fetching (installing) of gem that is in my internal repository.

I tried to install it using gem as well as bundler and both failed. Attached are the logs, the first test was using gem to install:

gem install amt_modules -v 1.0.3
jvm 1 | 2015-02-25 15:12:40,714+0000 WARN [qtp1997550262-52] deployment org.sonatype.nexus.proxy.storage.local.fs.DefaultFSPeer - Could not delete file: C:\nexus\sonatype-work\nexus\storage\gems-internal\specs.4.8.gz
jvm 1 | java.nio.file.FileSystemException: C:\nexus\sonatype-work\nexus\storage\gems-internal\specs.4.8.gz: The process cannot access the file because it is being used by another process.

second test was to setup bundler and once run I got an different exception:

bundle install
jvm 1 | 2015-02-25 15:18:43,261+0000 WARN [qtp1997550262-55] anonymous org.sonatype.nexus.plugins.ruby.proxy.DefaultProxyRubyRepository - Failed URL retrieve/cache: https://rubygems.org
jvm 1 | java.nio.file.InvalidPathException: Illegal char <?> at index 69: C:\nexus\sonatype-work\nexus\storage\rubygems-org\api\v1\dependencies?gems=amt_modules
jvm 1 | at sun.nio.fs.WindowsPathParser.normalize(Unknown Source) ~[na:1.8.0_25]