Why is water leaking out from the side tank

The external water tray is to be used for draining the unit when the internal water tray is full. Position the external water tray under the drain at the bottom rear of the unit then remove the cap and plug and let water fill the tray. This was copied from royal sovereign instructions.

First I'm not a Delonghi tech. But I have worked on similar table top "Super Automatic" machines. You should call your vendor for service as there is no customer serviceable parts in this machine.
*** the following is for information only. ***
* If your leaking at or under the water tank then check for crack or you may be missing a rubber seal, o-ring, or washer. Replace the whole tank as a unit.
* If your leaking into the dregs or drip tray then there is a problem with the brewing system. Call for service. They may need to replace the brew valve or PC board.
* If your leaking at the bottom, drip tray, or side only when the pump buzzes (pumping water) then there is a cracked or disconnected hose line or fitting. Call for service and replace.
* If your leaking when the steam wand is in use then there is a similar problem with the 2nd pump system. Call for service and replace.
* If your leaking liquid coffee into the dregs tray or drip tray. Then you have a worn or missing group gasket(s). Call for service and replace. (you may find gasket kits from Amazon.com or online.)
* Final; Leaking water and electrical equipment is not a good idea. Best to be safe. Unplug and call for service.
Aloha, ukeboy57

VPR has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the tank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

VPR has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the tank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

Either the freeze plug you installed is still leaking or you have a cracked block.

The water is coming from a leaking water tank behind the deli/meat tray. It only leaks when you use the water dispenser. You will need to disassemble the deli drawer to get to the water tank and replace the water tank. FOR THE WASHER, call Samsung for service. You may have a control board problem.

It can be due to an overflow of the drain tank that is at the rear bottom wherein when the defrost timer works , the frost condenses down to this tank.
It can also be a leak in the pipe line to the tank that causes the water to flow out.
It can be due to condensation within the door side that is flowing out., or even the collection tray leaking over , crust of frost falling out of the tray.

I believe that model has a catch tray under the coils which catch the droplets of water and route that water into the tank. First, make sure your unit is pretty level. Then take a look at the bottom of the coils for the catch tray to make sure it's not dislodged or not level. Lastly check the catch tray outlet to make sure it's not blocked and will allow water to flow easily into the tank. The other thing is to make sure the tank is inserted correctly, and the catch tray water is routed into it. You don't mention if it ever worked correctly, but if this unit has been working for a long while, it may be dirty and you need to clean it to get the water to drip down correctly.

This happens when the boiler develops a leak, usually due to scale buildup. Order a new boiler and o-rings and replace.

Dear ziba1--posted the same problem two days ago and it doesn't appear to be on the site yet. Anyway, picked away at this again today (literally took the machine apart) and found the problem to be a clog in the drainage system. This explains why your external tank will not fill and why there is a leak--the drip tray under the compressor is not draining due to the clog in the drainage system. I fixed this simply by taking a narrow device and gently scraping out the drain hole of the drip tray (which is located just below the compressor...the compressor is located on the same side as your air filter). After successfully cleaning out this drain, I proceeded to flush the water out thoroughly with water. Give it a try--worked for me. I had all but given up and had already set up an appointment to have it serviced. Cheers