How To Export and Import Multidoge Private Key to Dogecoin Core or Exodus or Others
In Multidoge, to transfer your wallet coins out of Multidoge and into another wallet program (such as Exodus), you must first export the private key file from Multidoge, by Tools, Export Private Keys, but very importantly you must chose the non-default option of not using a password, "Do not password protect export file." Then other programs can read it. Otherwise, if you don't, then the other wallet program you are trying to import your key into will say "Invalid private key; please check and try again!" or something else like that. Ignore the red warning underneath when you choose that no-password option, "Anyone who can read your export file can spend your dogecoin", as you have no choice, and of course you should protect that file just like you would protect any unencrypted private document. (This is all on the bottom half of the screen, regarding the export file. Of course, you must still enter your wallet password in the top half.)
When you export this way with no password, you get another key file which looks very different from the default password protected file, with a lot of English language text in the no-password file instead of only code in the password protected file. In the no-password file, there is lots of English text, after which there is one line which was not commented out by #, which is the private key in code, plus a datetime stamp, just one line near the bottom and in between comment lines. That is the one and only line you need to copy and paste into the other program. Other programs do not read a key file. They require you copy and paste your key.
However, if you copy that whole line, then it still will not import into another wallet, with an error message about invalid key or whatever. Reading the big key file more closely, it says the private key is Base58 encoded, followed by whitespace and the datetime stamp (obviously not in Base58 as you will see). So, copy only the Base58 string from the start of that line up to before the one whitespace character, with no whitespace character and no datetime stamp in what you copy, and paste that substring into the other wallet. Bingo, it should work, and you should see your Dogecoin balance and choose whether or not to import it to your new wallet ID on your new program.
But where do you paste it into the other program? It depends on which program.
If you don't want to download the tens of gigabytes of Dogecoin blockchain for Doge Core, then you can do this by switching to a third party program such as Exodus with its own wallet.
Exodus has Windows, Linux, Mac, Android, and iPhone versions. (I have experience with only the Linux and Windows versions.)
In Exodus, first enable Dogecoin on the Exodus tracking screen via Settings. Then from Settings go back to the tracking screen. On the tracking screen, click on Dogecoin, which will put you onto a Send Receive screen, which also has on the top right a vertical 3 dot More pulldown menu. On that 3 dot pulldown menu, choose "Move Funds". Put your Base58 private key in there without the datetime stamp and without any whitespace. Bingo! You should see the total amount of your Dogecoin and be able to move it into this new program.
If this has been helpful to you, and if you have a lot of Dogecoin, then please consider donating some to our cause. Just see our home page.
This website has a lot of text content, so here are some suggestions on how to navigate and also recognize pages you're seen already vs. still unseen pages in the SiteMap.
The pulldown menu and the SiteMap are the same tree of pages and links. The pulldown menu offers + and - for expand and collapse sections/subsections/sub-subsections... of the tree, sometimes multiple levels, whereas the SiteMap has everything expanded with no + or - expand and collapse options so the SiteMap is much longer, compared to the pulldown menu if not fully expanded. You may just choose which of the two formats you prefer at a particular time.