Hi Guntis, welcome.
That error is due to the missing sendump you mentioned. I’m pretty sure that Pocketsphinx requires that sendump file so I’m sort of confused about why the Russian model doesn’t have one, but there must be a reason because nsh is the main Pocketsphinx developer so it isn’t a mistake. My suggestions for proceeding with this are as follows: the first step is to level-set and make sure that this works with Pocketsphinx outside of OpenEars (i.e. rule out, or discover, an issue with OpenEars that is causing this). Do you have a Linux VM or dedicated box you can install Pocketsphinx on and test the model? My other advice or an alternative step you might want to take (depending on how complicated it is for you to test on Linux) would be to ask Nickolay whether the sendump file is required and/or how to use the model with Pocketsphinx with no sendump, which you can do at the CMU Sphinx forums (or he might pop in and answer your SO question since he also follows the OpenEars tag): http://sourceforge.net/p/cmusphinx/discussion/help/
Something else to keep in mind is that if the DMP/dic files are large-vocabulary recognition files (i.e. contain a vocabulary that is large enough for general dictation tasks, with tens of thousands of words) they will be too big for offline speech recognition on a handheld device.