There are three ways how to do that to fix Cydia crashes after reboot:
First way (iFile):If you have iFile installed on your gadget then use two following tutorials for Windows and Mac to automatically install .deb file.
Second Way (iFunBox):If you're on Windows, download and run iFunBox. Make sure that you have iTunes installed because that programs uses some of iTunes libraries to work properly. Connect you device to PC via USB cable. Find Cydia Install icon in the program's left menu and simply drag-and-drop the .deb file there. Reboot. The package will install automatically.
Third Way:With any file manager navigate to device's var->root->media->Cydia->Auto Install folder. If it isn't there - create it. Place the downloaded .deb file there. Reboot your device. The package will be installed during reboot. That's basically how to fix Cydia crashes after reboot by reinstalling Mobile Substrate. If you have any questions about that, something didn't work properly or you know some other ways how to do that - write us in the comments below.
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