Corrupted file when storing signal values from Simulink using the "to file" block

Hi everyone, I experience a tricky problem regarding the "to File" block when using a Simulink diagram in external mode. Regardless the output data type declared in the block dialog (time series or array), Simulink produces only a corrupted .mat file that causes a sudden crash when trying to open it. Further, it seems to be no way to fix it and making it reusable (solutions found in Matlab forum resulted ineffective). Have someone faced a similar issue and can help me solving this problem? I know I can turn to a "to workspace" block and save the data locally afterwards, but this way has show similar drawbacks and seem to be ineffective too. For the sake of clarity, I'm using Ubuntu 14.04 and Matlab R2014b, and Simulink runs in external mode with a fixed sample time. Thanks in advance