If you are getting out of memory, you can set a higher memory limit using the -Xmx command line argument. For example, -Xmx4096m sets Spine to use up to 4096MB (4GB) of RAM. However, 3.8 (all versions before 4.0) are 32-bit and Windows limits 32-bit programs to around 1200MB of RAM (-Xmx1200m). The actual limit by Windows varies and may be affected by other processes you have running. Setting higher than 1200MB for < 4.0 Spine versions may cause them to be unable to run, but you can try it.
The defaults are 1024MB for < 4.0 and 2048MB >= 4.0. The actual memory usage limit can be a little higher, and these numbers don't include GPU memory. Lastly, 4.0 is more efficient in many ways and it's very rare to need to increase the default of 2048MB.
Since the crash is happening when the project is loaded, I would guess that your project contains a lot of data. I highly suggest moving to 4.1+ as the problem will only get worse as you add more to your project in 3.8.
