Symptoms:
When tried to start mvsn manually using the below command that is also giving error as "No such file or directory". But the file is present in the directory.
FNPLicenseServerManager# ./lmgrd -c /opt/FNPLicenseServerManager/licenses/license.lic
(lmgrd) (@lmgrd-SLOG@) === Network Info ===
(lmgrd) (@lmgrd-SLOG@) Listening port: 27000
(lmgrd) (@lmgrd-SLOG@)
(lmgrd) (@lmgrd-SLOG@) === Startup Info ===
(lmgrd) (@lmgrd-SLOG@) Server Configuration: Single Server
(lmgrd) (@lmgrd-SLOG@) Command-line options used at LS startup: -c /opt/FNPLicenseServerManager/licenses/license.lic
(lmgrd) (@lmgrd-SLOG@) License file(s) used: /opt/FNPLicenseServerManager/licenses/license.lic
(lmgrd) (@lmgrd-SLOG@) ===============================================
(lmgrd) Starting vendor daemons ...
(lmgrd) Started mvsn (internet tcp_port 59453 pid 21623)
(lmgrd) license daemon: execute process failed: (./mvsn) -T cop 15.12 2 -c :/opt/FNPLicenseServerManager/licenses/license.lic:
(lmgrd) license daemon: system error code: No such file or directory
(lmgrd) mvsn exited with status 45 (Child cannot exec requested server)
(lmgrd) Please correct problem and restart daemons

Diagnosis:

The version of lmgrd should match that of the mvsn vendor daemon. If you are running 64 bit lmgrd and 32 bit mvsn on 64 bit machine, it will throw no such file or directory.

Solution:

You need to run the same version of lmgrd and the mvsn vendor daemon to avoid the no such file or directory error.
If you are running 64 bit lmgrd and the mvsn version also 64 bit. If you are using 32bit lmgrd then the msvn version also 32bit.

Also to run 32 bit version of lmgrd and mvsn on a 64 bit Ubuntu machine, need to use the following command
sudo apt update
sudo dpkg --add-architecture i386
sudo apt update
sudo apt install libc6:i386 libstdc++6:i386 libncurses5:i386 zlib1g:i386
sudo ln -s /lib/i386-linux-gnu/ld-linux.so.2 ld-lsb.so.3