There are a number of exceptions occurring in your log. Did you reduce the Memory Cache size to 256MB?
Do you have a color profile assigned to your display? What macOS version are you using on your system?
What are the exceptions? Errors?
Essentially, yes. Looks like low memory conditions to me. Reducing the Memory Cache size should help. PM5 is a 32-bit application and as such can only use a maximum of 4GB of RAM, much of which is taken up by PM's application code, shared libraries, and data structures unrelated to the images themselves.
If reducing the Memory Cache to 256MB or even 128MB doesn't help then I suggest contacting our support folks at:
By email: support@camerabits.com
By phone: +1 503.547.2800 option 2
Hours: Mon-Fri, 9:00am-5:00pm [PST/PDT]