Solution
The error -1950679023 is due to the system that is hosting your shared variable being unable to find the shared variables. This could be caused by:
1. A bad connection between the PC and the cRIO device or a dip in the power supply of the installation
This sort of behaviour can be characterised by network instability or the cRIO device disconnecting periodically from the host device. Errors in the network can often be analysed using third party tools like Wireshark.
2. The Shared Variable Engine (SVE) is crashing momentarily
If you are using a LabVIEW Real-Time target such as CompactRIO or Compact FieldPoint, you should consider hosting the shared variable library on the real-time target. These devices have watchdog capabilities and typically contain hardware components controlling the critical pieces of an application, whereas most Windows or PC-based targets do not have these fail-safes.