As of version 126.96.36.199 released in August 2021 DidiSoft OraSFTP offered ZLIB compression which greatly increased the speed of the SFTP communication.
Unfortunately, the ZLIB package we used (JZlib) had a bug that resulted in ArrayIndexOutOfBoundsException on random occasions. This is very strange as this is the only Java ZLIB package with partial flush capabilities (the built into JDK Deflater doesn’t support partial flush) and it should be very robust as it is used virtually in every Java-based system with SFTP support.
After some recent investigation, we have fixed this bug in JZlib and it is available in version 188.8.131.52 of OraSFTP.
Recommended upgrade to OraSFTP version 184.108.40.206
If you are using DidiSoft OraSFTP from version 220.127.116.11 to 18.104.22.168 it is recommended to update to version 22.214.171.124 in order to have a smooth operation in ZLIB compression mode.