I analyzed the file using STAAD.Pro SS6 ( version 20.07.11.50 ) and also older versions like SS5 ( version 20.07.10.65 ) & SS4 ( version 20.07.09.31 ) and I am not able to replicate the crash. Since you mentioned that you are able to go to the postprocessing mode sometimes whereas the file crashes at other occasions, here are some suggestions.
1. Please ensure that the file being analyzed is on a local drive in your machine and NOT on a network drive.
2. Please create a new folder in your local machine, copy ONLY the .std file in that folder from outside the STAAD.Pro environment. You may use windows explorer to copy the file. Analyze it and see if you get the crash.
Last but not the least, the version 20.07.04.12 is a very old version and I would definitely suggest that you update the software to the latest version.
1. Please ensure that the file being analyzed is on a local drive in your machine and NOT on a network drive.
2. Please create a new folder in your local machine, copy ONLY the .std file in that folder from outside the STAAD.Pro environment. You may use windows explorer to copy the file. Analyze it and see if you get the crash.
Last but not the least, the version 20.07.04.12 is a very old version and I would definitely suggest that you update the software to the latest version.