Thanks for your reply
As you say, I updated my old instance in order to get my database updated. By the way, I tested my new instance, and you are right, I tested myself that this new version was very unstable.
Then, I installed a new instance of sugarcrm version 6.1.7, connected with new database, and customized almost everything -this is a work tired, but in this way I will have my sugar updated safely

- I still have to clone two modules: documents and bugs. Because in my business's sugarcrm 4.2.1d we had four modules for this: public documents, private documents, internal bugs, external bugs.
What is the safest way to clone one sugar's module?
Excellent forum! Daniel
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