Cannot Open Flex2SQL at the Second Time

After downloading the setup and installing it, you can open and migrate tables properly using Flex2SQL. But if closing it and trying to open it again you receive the message below and can't more open the Flex2SQL:

can't open table TABLE=flexerrs(247)
erro number: 75
line number: 113789

This issue is due you don't have the flexerrs.dat in the new filelist.cfg you selected to convert the tables neither have it in the PATH. To fix it, just copy the flexerrs.dat to the folder from the filelist.cfg you selected or add one folder that has the file in your PATH.