Indicator Maintenance is required and it is safe process. All you need to do is to click
"NEXT" without changing / selecting /deselecting any checkboses.
If you do everything should be fine.
To be safe, Indicator Maintenace makes a BACKUP of vital file (broker.newcharts) that holds
references between charts and formulas.
The backup is stored as "broker.newcharts.bak" in AmiBroker directory.
You can revert to pre-Indicator Maintenance state simply by restoring that backup,
i.e. deleting broker.newcharts and renaming broker.newcharts.bak back to broker.newcharts.
In a followup message this further explanation was provided:
What is limited is number of references between layouts and formulas,
i.e. so called "ChartIDs" there are 3000 of them. ChartIDs are needed for two
purposes: to link parameters to charts and to make study() function possible.
These chart ids are re-used as you delete / close chart (i.e. if you delete / close chart) and given ID is not
used anywhere in any layout it can be reused. Sometimes given chart ID may not
be immediately marked for re-use. Indicator Maintenance is looking for those leftover
unused chart IDs that can be re-used.