user117304: Basically I made a purchase with bitcoins back in ~2014 and I remember that I had a little bit leftover. However all documentation I have is a file labelled wallet with a huge string of characters. But when I try and access it on any application I get the non base-58 character error. There are a bunch of +'s and /'s. Does anyone have any idea what I could try to see if this is it? Sorry for not having more advance knowledge.

user13866: 
There are a bunch of +'s and /'s.

That strongly suggests it is data in Base64 encoding. Note that, in this case encoding does not mean encryption, just a specific printable representation of binary data.

Does anyone have any idea what I could try to see if this is it?

It seems several different wallets might use Base64 encoding, including:

Blockchain.info backup using AES encrypted JSON

Bitcoin Wallet for Android (Schildbach wallet)

Print wallet.dat with base64


Of those, I'd guess the first is most likely. But that's just a guess. There are probably numerous other possibilities.
I think I'd try the Blockchain.info recovery process first then, if that didn't work, try decoding the file from Base64 into binary and using a hex editor to look for patterns that might give some clues to the software that produced it. If the file is encrypted using a wallet password this probably would not be fruitful.

117304: <p>Basically I made a purchase with bitcoins back in ~2014 and I remember that I had a little bit leftover. However all documentation I have is a file labelled wallet with a huge string of characters. But when I try and access it on any application I get the non base-58 character error. There are a bunch of +'s and /'s. Does anyone have any idea what I could try to see if this is it? Sorry for not having more advance knowledge.</p>
 13866: <blockquote>
<p><strong>There are a bunch of +'s and /'s.</strong></p>
</blockquote>
<p>That strongly suggests it is data in <a href="https://en.wikipedia.org/wiki/Base64#Base64_table" rel="nofollow noreferrer">Base64 encoding</a>. Note that, in this case encoding does not mean encryption, just a specific printable representation of binary data.</p>
<blockquote>
<p><strong>Does anyone have any idea what I could try to see if this is it?</strong></p>
</blockquote>
<p>It seems several different wallets might use Base64 encoding, including:</p>
<ul>
<li><p><a href="https://www.reddit.com/r/Bitcoin/comments/cx3zd1/found_a_2014_file_on_my_computer_called_bitcoin/" rel="nofollow noreferrer">Blockchain.info backup using AES encrypted JSON</a></p>
</li>
<li><p><a href="https://github.com/bitcoin-wallet/bitcoin-wallet/issues/367" rel="nofollow noreferrer">Bitcoin Wallet for Android (Schildbach wallet)</a></p>
</li>
<li><p><a href="https://bitcoin.stackexchange.com/q/13482/13866">Print wallet.dat with base64</a></p>
</li>
</ul>
<p>Of those, I'd guess the first is most likely. But that's just a guess. There are probably numerous other possibilities.</p>
<p>I think I'd try the Blockchain.info recovery process first then, if that didn't work, try decoding the file from Base64 into binary and using a hex editor to look for patterns that might give some clues to the software that produced it. If the file is encrypted using a wallet password this probably would not be fruitful.</p>
