Hello @0nly4phil,
you updated to 4.1.3 from which version? What extensions does workflow need in order to run? Can you maybe share workflow?
Additionally you can check your log files. Please make sure to put log level to DEBUG.
(This is done within KNIME if you go File --> Preferences --> KNIME)
Here is location of log files to check after crash occurs:
...\knime-workspace\.metadata\knime\knime.log...\knime-workspace\.metadata\.log
If sharing logs here please make sure to exclude sensitive data, if any.
Br,
Ivan