#2394 Install packages on-the-fly for all users fails with Windows API error 87

[BD R]

When typesetting a file with missing dependencies, MikTex / TeXworks prompts to download and install the missing packages "on-the-fly".

However, the package installations fail with error: "Unfortunately, the package colortbl could not be installed.Please check the log file: C:/Users/Barry/AppData/Local/MiKTeX/2.9/miktex/log/miktex-pdftex.log"

The log file contains:

INFO miktex-pdftex - mpm: downloading http://mirror.math.ku.edu/tex-archive/systems/win32/miktex/tm...
INFO miktex-pdftex - mpm: 1362027 bytes, 11.85 KB/Sec
INFO miktex-pdftex - mpm: extracting files from microtype.tar.lzma...
FATAL miktex-pdftex - Windows API error 87: The parameter is incorrect.
FATAL miktex-pdftex - Info: C:\ProgramData\MiKTeX\2.9\miktex/data/le\b1cfc6be702f63eea92ca0fbc9559e5c.fndb
FATAL miktex-pdftex - Source: Libraries\MiKTeX\Core\win\winMemoryMappedFile.cpp
2015-09-03 07:09:21,479-0400 FATAL miktex-pdftex - Line: 120

As you can see, there is no issue downloading & extracting the package. This seems to happen because TeXworks is open. If I close TeXworks and use MiKTeX package manager, I can install whichever packages I like.
It seems like there is some file lock issue with the FNDB.

[BD R]

Update: This issue only occurs when installing packages "for all users". When I install for the current user only, the package installs fine and pdflatex continues successfully.

[Christian Schenk]

Thank you, this will be fixed with one of the next updates.

[Tricolore]

I'm also having problems with one package that MiKTeX attempts to install on-the-fly:
Unfortunately, the package preprint could not be installed.Please check the log file: C:/Users/<user-name>/AppData/Local/MiKTeX/2.9/miktex/log/pdflatex.log