Hi
Today I upgraded from version 8.x to 12.0.1 It looks great.!! 
But I can’t see all modules (invoices, products, accounting, etc) in Setup->Modules/Application setup to set my preferences.
Any idea?
OK. I fixed it already.
I leave it here documented in case it happens to someone else:
1- My site had version 8.0.1 and I wanted to upgrade to 12.0.1. After following the step-by-step instructions the installer guides you to upgrade the databases to version 9, then to 10, then to 11 and finally to 12
2- After the upgrade, all looks fine but when I went to the module setup, I realized I only had a few modules and the rest weren’t showing.
Since I didn’t get any answers on this forum, I went to check the databases. I suspected that the problem might be in the constants so after checking the code of /admin/modules.php and its libraries, I went straight to the “llx_const” table. Eureka! 
For some reason, during the update process, some fields for ‘MAIN_MODULE_xx’ entry were left with a NULL or empty value. Coincidentally, the modules that were not shown in the configuration area:
For example:
llx_const.name: ‘MAIN_MODULE_ACCOUNTING’
llx_const.type: NULL (must be string)
llx_const.note: empty (must be {“authorid”:“1”,“ip”:“my_ip_addrs”})
Possibly for some people, this has been an unorthodox method but I am happy to have all the modules in this section back again
@richmond, Thanks for this
However, is there now a more clearer way to slove this considering a higher dolibarr version?
The Application /Module page is blank and i cant setup any module
I downloaded PrintJS, did the system way of installing and that was it - Page disappeared
Dont know how to access my DB and to make the changes you made
Can you guide?
