Weird. There’s another thread going on that’s getting the same error, also using the multi-file uploader. I’ve never used it, so my experience is nonexistent with it. Hopefully someone else has some insights!
The problem is that the link is taking the URL of a list of files, which is effectively a list of texts.
When a list of texts is represented as one text, by default they are joined together with a comma.
So your link has something like this, which the browser then matches it to https or http whichever is appropriate … //s3.amazonaws.com/appforest_uf/f1533734573125x978449569316580900/%5E5404CB18CCA4E55EFFD1D6A1033F5B88670116D1767B2ACF80%5Epimgpsh_fullsize_distr.jpg,%20//s3.amazonaws.com/appforest_uf/f1533734573641x486278980504721400/1236996_466570603546171_265849568834733064_n.jpg
It would be a useful diagnostic step for you to display a text link with the same text as the link.
What comes next? A design decision, which file to display in the link, or do you want to have a list of links?
To show just the first link, put :first item to specify you are dealing with one file …
Proposal :first item's URL
Or, to show links to them all, create a repeating group, set its data source to be the list of files i.e. Proposal, and inside the group have a link for each item …
Current cell's URL
Another option is using a bit of regex to create all the links in a single text. I can post that too, if it will be useful.