I have migrated our sharepoint on-premises 2013 team site collection to sharepoint online classic team site. and on all the on-premises document libraries we major/minor versions enabled and the major limit = 50, as follow:-
and on the migrated online document libraries i got the same settings. but if i edit these settings and i click on Save without changing anything, i will get this error message "You must enter number between 100 and 50000", as follow:-
so i can conclude that on sharepoint online document libraries we can not specify the limit to be 50.. and it should be between 100 & 50000. but since i just completed the migration and everything went smoothly, so i need to keep the site collection as-is with less modifications during this week, till i am sure that everything is working well. so my first question is, if there will be any harm if i keep the major version limit = 50? although seems sharepoint online does not allow this number for brand new document libraries?
second question, if i increase the major version limit from 50 to 100, can this cause any problem or any data loss , or since i am specifying a larger limit number (100 instead of 50), then there should not be any issue?
You will not lose data by increasing the number of version. SharePoint online is enforcing this option as of a few months back and the minimum is 100. A back end job will probabaly end up changing these for you after awhile but changing them manually if you need to make other changes will not be an issue.