I am no expert, but I think you installed a version of EPM, which is not supported by your contract. Usually, there are e.g. 10-year licenses with only 1 year of updates.
So you have to go back to the last version, which worked.
Why dont you use the module-admin for the downgrade?
Do you use EPM with non-Sangoma phones? If yes, you need a new EPM update license. If no, contact Sangoma so that your license is switched to the free version of EPM