Hi Alex,
Greetings from Syncfusion support.
We have checked with your reported query “Is there a file upload limit? We're trying to upload 148 files (rough size 50kb each) and the upload control is not working at all.”
We were unable to replicate the reported issue for the mentioned file size. Please share the replication steps for reported issue and also confirm you are using normal uploader or chunk uploader. If the file request failed in the network tab, please share the screenshot of the error message. It would be helpful to analyze the issue further at our end.
Please find the sample below for your reference.
Kindly get back to us for further assistance.
Regards,
Sevvandhi N