GOTOES gets very heavy usage on a daily basis - some of it from robots and illicit sources. Therefore, there is the need to place limits on how large of a file can be uploaded to the tool. If too many large files are uploaded at once, legitimate users will receive slow page load times and have a poor experience. There are ways for you to work-around the size limits:
Strategy 1: ZIP Compress Files
If you are uploading GPX, CSV, or TCX files to the tool, try zipping them. This will make the files MUCH smaller. The tool is most efficient at handling these types of files, so this strategy is your best option - unless you need the extra data contained in FIT files (if so, see next option)...
Strategy 2: Shrink bloated FIT Files
FIT Files tend to be MUCH smaller than GPX or TCX files for the same amount of data. However, FIT files require more processing power. If you are uploading FIT files, and the tool still cannot process them, this step is for you. I have seen problems with certain FIT files. Wahoo files tend to contain a lot of extra junk that sometimes can crash the tool. Also, if you have "Heart Rate Variability" being recorded inside your FIT files, the extra amount of data can be so much, it can crash the tool. In this case, your first option should be to try and de-bloat your FIT files using my FIT to CSV Converter. This option may seem a little counter-intuitive; the CSV file you get from my tool is much larger than the FIT file you started with. However, even though the file is large, it has the extra "FIT Junk" removed. Simply zip compress the CSV files you get from my tool, and then re-upload it to the merger and they will process much more quickly.
Strategy 3: Remove Excess Points
A lot of people like to use 1 second recording to get "All the Data". 1 second recording is great for your 5 hour bike rides, but if you're doing an ultra-marathon that takes 24 hours or trying to merge a bike ride across a country, 1 second recording is just too much for my tool (and it is too much for Strava to display their maps correctly). If you're trying to merge files that have just too many points, you can upload them one-at-a-time to the tool and use the "Discard Track Points" Feature, and then re-export the files. Don't worry: if you have a point every 5 seconds instead of every 1 second, it will still look great on Strava. After you shrink and export all of the files, you can re-import them for a merge and they should process much faster. Remember that you can combine Strategies 1 and 2 with this Strategy 3. I have a discussion on discarding extra trackpoints here