when I launch mcreator, it issues a notification that it is not possible to connect to the pylo servers and when I export the mcreator mod, it simply closes and the mod is not exported, I cannot install a newer version because I need to make the mod exactly for the minecraft version 1.7.10
1.7.10 is fully outdated and uses protocols no longer supported for a while now
Since there is no official download anymore you must have gotten it from some illegal source that could be distributing modified version that we have no control over so I highly advise against doing this