I have been having repeated crashes with Explorer++ Portable 1.3.5. I contacted the developer who said "I no longer investigate any issues specific to 1.3.5. If the crashes occur in the latest development build, please send through a crash dump."
The development build is 1.4.0. It is marked as a beta, but is the only version supported. https://explorerplusplus.com/download.
I feel that 1.4.0 should be used as the current portable version as version 1.3.5 has been depreciated.